EMORY UNIVERSITY SCHOOL OF MEDICINE Department of Orthopaedics

The Kelly Society Orthopaedic Journal

2018

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Table of Contents Letter from the Chairman 2 Letter from the Residency Director 3 2018 Kelly Society Visiting Professor 4 Kelly Day Agenda 5 PGY-5 Class 8 PGY-5 Bios, Manuscripts, and Abstracts 10-59 Laura Bellaire, MD 10-15 William Carpenter, MD 16-17 Jimmy Daruwalla, MD 18-24 Anuj Patel, MD 25-39 Robert Runner, MD 40-59 PGY-3 Manuscripts 60-126 PGY 1-4 Residency Classes 127 Emory Orthopaedics Surgical Faculty 128 Kelly Day Visiting Professors 129 Recent Publications (2017 – 2018) 130

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LETTER FROM THE CHAIRMAN

Scott D. Boden, MD

We have a long tradition of outstanding leaders of our profession who have taken time from their personal and professional schedules to serve as the Kelly Day Visiting Professor. Dr. Vitale clearly ranks as a leader in Orthopaedics today, and I am particularly grateful to Dr. Vitale for being with us and enriching our educational program.

I also want to acknowledge the 15+ years of dedicated and unselfish service Dr. Jim Roberson has provided to the Department, and the tremendous growth and expansion that has taken place under his Chairmanship. We can all be proud of how the Department has changed and grown. We have seen the faculty more than double in size, including a stable, excellent group of full time Grady faculty. In addition to being among the most clinically busy services at Grady and the VA Hospital, the MSK service line has become a critically important component of Emory Healthcare with approximately 1 out of every 3.5 new patients to Emory entering through Orthopedics.

The blend of clinical efficiency, academic opportunities, and diverse patient care environments have resulted in the Emory Orthopaedic Residency and Fellowship training programs becoming increasingly among the most sought after in the country. In the coming years we will expand our fellowship offerings to include Upper Extremity, Trauma, and Pediatrics.

We are now also undergoing a major expansion of our basic/translational and clinical research team. Our Vice-Chair for Research, Hicham Drissi, PhD, and our Director of Clinical Research, Michael Gottschalk, MD, are leading those efforts with outstanding early successes.

Support and contributions from the alumni are increasingly needed to enhance the support for resident education and research, which are an integral component of these Department achievements. Thank you for your continued support.

With sincere appreciation for each of your efforts that contribute to Team MSK,

Scott

Scott D. Boden, M.D.

Scott D. Boden, MD Professor and Interim Chairman Department of Orthopaedic Surgery Emory University School of Medicine

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LETTER FROM THE RESIDENCY

DIRECTOR THOMAS L. BRADBURY, M

Kelly Days 2018 is truly a special event! It is an honor to host Dr. Michael Vitale as the 2018 Kelly Visiting Professor. Among is innumerable accomplishment, Dr. Vitale is widely recognized for his innovative work focusing patient safety and quality improvement in pediatric spinal surgery. We are fortunate to briefly pause from the “daily grind” to spend time with him discussing our research initiatives and ways to improve the care we provide. Dr. Vitale, thank you!

Most importantly, Kelly Day weekend gives us the opportunity to recognize the accomplishments of five very special individuals. Although Anuj, Jimmy, Laura, Robert, and Will are very unique as individuals, they share a very common thread: THEY CARE!

Over the past 5 years, they have dedicated almost every waking hour to the pursuit of knowledge, skill and the care of their patients. When an individual was faced with adversity, they responded by caring for each other. They have defined what it means to be a team. In my mind, they embody our Residency Program’s ultimate objective: To be the kind of doctor you want for your own family.

Please join me this weekend in celebrating the achievements of this outstanding group!

Tom

Tom Bradbury, MD Adult Reconstruction, Assistant Professor of Orthopaedic Surgery

Orthopaedic Surgery Residency Program Director

Emory University School of Medicine

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2018 KELLY SOCIETY VISITING PROFESSOR

MICHAEL G. VITALE, MD, MPH

Dr. Michael G. Vitale is a leading New York Pediatric Spine Surgeon. He is the Ana Lucia Professor of Pediatric Orthopaedic Surgery at Columbia University Medical Center, Director of the Division of Pediatric Orthopaedic Surgery, and the Chief of the Pediatric Spine and Scoliosis Service at Morgan Stanley Children’s Hospital of New York – Presbyterian.

He specializes in spine surgery as well as non-operative treatment of complex pediatric scoliosis and other spinal disorders. He has a special interest in the treatment of patients with Early Onset Scoliosis. As a leading spine surgeon, he has pioneered numerous innovative surgical techniques, and has developed spinal instrumentation systems to improve the care of children with scoliosis.

Dr. Vitale received his Masters of Public Health from Columbia University Joseph Mailman School of Public Health and his Doctor of Medicine from the College of Physicians and Surgeons of Columbia University, which was followed by a residency in Orthopaedic Surgery at Columbia-Presbyterian Medical Center and a one year fellowship at the Children's Hospital of Los Angeles in University of Southern California.

Currently, he serves as the director of the Pediatric Orthopaedic Research Group, and has over 100 peer reviewed research publications in the field of pediatric orthopaedics, including a number of efforts leading national guidelines aimed at improving quality and safety of pediatric spine surgery. He has received numerous national awards from the Pediatric Orthopaedic Society of North America including the Arthur H. Huene Memorial Award, the Angela M Kuo Award Young Investigator Award, the Robert Hensinger Scientific Paper Award, as well as the Hansjorg Wyss Research Award, the Frank Stinchfield Research Award, the Rosamond Kane Award in Pediatric Orthopaedic Surgery, and the Harrison Mclaughin Award. Addtionally, he is the recipient of the Castle Connolly’s Top Doctors award for 5 consecutive years and has been named in 50 Physicians in the US in the area of Scoliosis Care by Becker’s Spine Review.

Dr. Vitale also serves numerous roles in the national governance of the field—currently serving on the Board of Directors of the Pediatric Orthopaedic Society of North America, chairing the International Pediatric Orthopaedic Society, leading the efforts of the Scoliosis Research Society on Advocacy for Unmet Needs of Children for Pediatric Medical Devices, serving on the Executive Committee of the Children’s Spine Study Group, and is a Member of the International Pediatric Orthopaedic Think Tank.

He also leads the Conservative Treatment of Scoliosis Center, with Co-Director Hagit Berdishevsky. One of the only programs of its kind, the Center focuses on avoiding surgery with attention to scoliosis specific Schroth physical therapy and state-of-the art expert brace options including the Rigo System Cheneau brace. For the youngest children with scoliosis, Dr. Vitale runs an active Mehta casting program and has successfully used this method to reverse spinal curvature in numerous patients.

Most recently, he has developed a career interest in the area of Quality Improvement, leading the research arm of the Pediatric Orthopaedic Society of North America’s Committee on Quality, Safety, and Value, serving as the Medical Director of New York Presbyterian’s Initiative to Make Care Better, and serving as the Chief Quality Officer of the Department of Orthopaedic Surgery at Columbia University Medical Center.

Dr. Vitale is an avid skier, marathon runner, and recreational triathlete. Most of all, he enjoys spending time with his wife and four sons.

Michael G. Vitale, MD, MPH Ana Lucia Professor of Pediatric Orthopaedic Surgery, Columbia University Medical Center Chief, Pediatric Spine and Scoliosis Surgery Co-Director, Division of Pediatric Orthopaedics Chief Quality Officer, Department of Orthopaedic Surgery

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2018 KELLY SOCIETY GUEST LECTURER

CRAIG KRONENBERGER

Craig Kronenberger, also known as the “The Fist” is a reputation and crisis management expert.

With more than twenty years of experience in digital communications, Craig has championed and led strategy for clients such as Paul Allen, Sheikh Al Amoudi, the White House, Disney, Amazon, GE and the country of Belize.

A serial entrepreneur and communications innovator, Craig has started companies spanning video distribution, online gaming, digital marketing to technology patents. Building on the expertise gleaned from his entrepreneurial endeavors, Craig also gained deep in-house, agency experience and served as the Global Managing Director of Strategic Growth at Edelman, the largest private communications firm in the world. At Edelman, Craig focused on identifying, operationalizing and incubating emerging capabilities for the firm. His work included areas in paid advertising, digital crisis, analytics and search marketing.

Craig also led the Southeast region for iCrossing, where he developed and on-boarded the global search governance program for Coca-Cola, which encompassed more than 200 countries and multiple brands and divisions. Craig was also instrumental in leading the digital strategy for several of CNN’s key digital products including video integration.

Prior to these roles, Craig served as Global Practice Lead for Search Marketing at Modem Media/Digitas, where he was instrumental in localizing media practices in Europe and the U.S. As practice lead, Craig led the development of the global search strategy for HP and General Motors. Prior to leading the search practice, Craig helped build the Delta's first direct marketing initiative online, which drove over $150M in airline ticket sales through the integration of paid media and a new booking engine.

Craig received his BFA in Electronic Media and graduated from the University of Cincinnati’s Conservatory of Music.

Craig is also a co-owner of Paid Search Engine Tools, which holds several patents in search technology and bid management. He has been repeatedly recognized in the media as a leader and visionary within the digital space and has appeared on The Today Show, Wall Street Journal and CNN. Sharing his expertise with future communicators and strategists, Craig has also taught and lectured at Emory University, University of Cincinnati, Florida State and Georgia Tech.

.

Craig Kronenberger, BFA President and Founder of Stripe Reputation

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2018 KELLY DAY AGENDA

7:00 AM Registration & Breakfast 7:45 AM Welcoming Remarks

Scott Boden, MD Professor and Interim Chairman Department of Orthopaedic Surgery Emory University School of Medicine

Resident Research Presentation: Session I 8:00 AM The Impact of Prophylactic Intraoperative Vancomycin Powder on Microbial Profile,

Antibiotic Regimen, Length of Stay, and Reoperation Rate in Elective Spine Surgery Zachary Grabel, MD, PGY 3 8:10 AM Closed Suction Drainage in Acetabular Fracture Surgery: Is it Time We Take a Page from Our

Arthroplasty Colleagues? Adam Boissonneault, M.B.Ch.B., PGY 3 8:20 AM Risk of Osteonecrosis and Complications after Delayed Treatment of Pediatric Humeral Lateral

Condyle Fractures William Carpenter, MD, PGY 5 8:30 AM Utility of Intra-wound Vancomycin Powder in Arthroplasty Surgery Nick Patel, MD, PGY 3 8:40 AM Discussion:

Dr. Michael Vitale and Emory Faculty Pediatric Case Presentation 9:00 AM Early Onset Scoliosis

Presenter: Dr. Sandra Hobson, PGY 4 Panel: Robert Bruce, Nicholas Fletcher, Michael Vitale, Michael Schmitz

9:30 AM Coffee Break CHOA Lecture 9:45 AM Pediatric Femoral Shaft Fractures in 2018: The State of the Art

Michael Schmitz, MD Chief of Orthopaedics Children’s Healthcare of Atlanta

Friday, June 8, 2018

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Resident Research Presentation: Session II 10:20 AM Utilization Patterns, Efficacy, and Complications of Venous Thromboembolism Prophylaxis

Regimens in Primary Hip and Knee Arthroplasty as Reported by ABOS Part II Candidates Robert Runner, MD, PGY 5

10:30 AM A University-Based Orthopaedic ‘Focused Factory:’ Does It Provide Better Outcomes? Jimmy Daruwalla, MD, PGY 5 10:40 AM A Reproducible and Reliable Localization Technique for Lumbar Spine Surgery that Minimizes

Unintended Level Exposure and Wrong Level Surgery Anuj Patel, MD, PGY 5

10:50 AM Predictors of Extended Length of Stay after Posterior Spinal Fusion for Neuromuscular

Scoliosis Laura Bellaire, MD, PGY 5 11:00 AM Discussion: Dr. Vitale and Emory Faculty 2018 Kelly Day Lecture 11:15 AM Introduction of 2018 Kelly Visiting Professor

Nicholas Fletcher, MD

2018 Kelly Visiting Professor Michael Vitale, MD, MPH Ana Lucia Professor of Pediatric Orthopaedic Surgery and Neurosurgery Vice Chair, Quality and Strategy, Orthopedic Surgery Columbia University Medical Center Co-Director, Division of Pediatric Orthopaedics Chief, Pediatric Spine and Scoliosis Service Morgan Stanley Children’s Hospital of New York – Presbyterian Lunch Presentation: 12:30 PM “Your Reputation Matters….Don’t Blow it!”

Craig Kronenberger President, Stripe Reputation

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Resident Research Presentation: Session III 1:20 PM Total Disc Replacement Adjacent to a Multilevel Fusion in the Cervical Spine: A

Biomechanical Study Dale Segal, MD, PGY 3 1:30 PM Ultra sound Guided Aspiration of Wrist Ganglion Cysts does not Reduce Recurrence Gregory Kurkis, MD, PGY 3 1:40 PM Increased Resource Utilization in Medicaid Patients following Primary Total Hip Arthroplasty David Shau, MD, MBA, PGY 3

1:50 PM Discussion: Vitale and Emory faculty

Quality Improvement & Patient Safety Symposium 2:00 PM Managing Orthopaedic Complexity: People, Protocols and Systems

Moderators: Tom Bradbury and Nick Fletcher

Panel: Michael Vitale, Scott Boden, Will Reisman, Michael Schmitz, Bob Bruce Department of Orthopaedics Seed Grant & Basic Science Presentations: 2:50 PM Update and Introductions Hicham Drissi, PhD Nick Willett, PhD 3:00 PM Bone Marrow Aspirate Concentrate “Monotherapy” use in the Adult Rat Cartilage Defect Repair

Model: Intraarticular versus Intraosseous Injection. Briggs Ahearn, MD, PGY 4 Sameh Labib, MD Associate Professor, Sports Medicine & Foot and Ankle Surgery

3:10 PM PRIYA: Preventing Reinjury In Young Athletes Neeru Jayanthi MD

Associate Professor of Orthopaedics Associate Professor of Family Medicine Emory University School of Medicine Emory Sports Medicine Center

3:30 PM Closing Remarks

Scott Boden, MD and Thomas Bradbury, MD

**CME credits will be issued in January 2019. Please remember to provide your email address to receive your statement.

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2017 – 2018 Orthopaedic Chief Surgery Residents

PGY-5

Laura Bellaire, MD

Fellowship Match: University of Utah Salt Lake City, UT

Pediatric Orthopaedics

Medical School: Emory University,

School of Medicine Atlanta, GA

Hometown: Atlanta, GA

William Carpenter, MD Fellowship Match: NYU/ Insall Scott Kelly

Institute New York, NY

Adult Reconstruction

Medical School: Auburn University

Auburn, AL

Hometown: Waco, TX

Jimmy Daruwalla, MD Fellowship Match: Curtis National Hand Ctr.

Baltimore, MD

Hand & Upper Extremity

Medical School: Emory University,

School of Medicine Atlanta, GA

Hometown: Rockville, MD

Anuj Patel , MD Administrative Chief

Fellowship Match: Harvard University

Boston, MA

Spine Surgery

Medical School: University South

Alabama

Mobile, AL

Hometown: Gadsden , AL

Robert Runner, MD Administrative Chief

Fellowship Match: Hoag Institute Orthopaedic

Specialty Institute Irvine, CA

Adult Reconstruction

Medical School: Emory University,

School of Medicine Atlanta, GA

Hometown: Atlanta, GA

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PUBLICATIONS

Borden TC, Bellaire LL, Fletcher ND “Improving Perioperative Care for Adolescent Idiopathic Scoliosis Patients: The Impact of a Multidisciplinary Care Approach.” J of Multidisciplinary Healthcare. 2016 Sep 14; 9: 435-445.

Gottschalk M, Bellaire LL, Moore TJ, “Radiation Exposure in the Young Level I Trauma Patient: A Retrospective Review.” J Surg Orthop Advances. 2015 Spring; 24(1): 57-63.

Bellaire L, “Corticosteroid Injections.” Essentials of Musculoskeletal Care 5th Edition. American Academy of Orthopaedic Surgeons. Ed. John F Sarwark. 2014.

PENDING PUBLICATIONS

Skaggs D, Andras L, Fletcher N, Choi P, Bellaire L, Tolo V, “Don’t You Wish You Had Fused to the Pelvis the First Time: A Comparison of Reoperation Rate and Correction of Pelvic Obliquity.”

• Podium presentation given at Scoliosis Research Society annual meeting on September 8, 2017

• Publication pending in Spine (submitted 5/18/18)

Bellaire L, Bowman C, Fletcher N, Bruce R, “Is early discharge possible following posterior spinal fusion for neuromuscular scoliosis?”

• Podium presentation at the 2017 EPOSNA meeting

• Winner of the Kelly Society annual research award 2016

Fletcher N, Bellaire LL, Borden T, Bruce R, “Predictors of length of stay following posterior spinal fusion in neuromuscular scoliosis

Black J, Moore TJ, Yonz M, Bellaire L, “Ballistic Fractures of the Lower Extremity: a Review of Soft Tissue Complications from a Level I Trauma Center.”

• Podium Presentation at the Georgia Orthopaedic Society annual meeting

• Accepted for publication in the Journal of Orthopaedic Trauma, pending edits.

Laura Bellaire, MD PGY-5 Pediatric Orthopaedic Surgery Fellowship University of Utah Salt Lake City, UT EDUCATION: Emory University School of Medicine Atlanta, GA Doctor of Medicine, May 2013 Yale University, New Haven, CT Bachelor of Arts, May 2009

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Predictors Of Hospital Length Of Stay Following Neuromuscular Spinal Fusion

Nicholas D. Fletcher, MD, Laura L. Bellaire, MD, Eric Dilbone, MD, Laura Ward, Robert W. Bruce Jr. MD

ABSTRACT:

Background: Patients with neuromuscular scoliosis (NMS) who undergo posterior spinal fusion (PSF) have historically stayed in the hospital for greater than one week after surgery. These patients’ comorbidities, nutritional and respiratory compromise, and larger rapidly progressive curves put them at greater risk of complications and prolonged stay. Accelerated discharge (AD) protocols have the ability to reduce hospital length of stay without increasing complications, however a small subset of patients is not well suited to rapid mobilization and early discharge.

Methods: 197 patients with NMS underwent PSF between 2005 and 2013 by two surgeons. These patients were divided into quartiles based on their hospital length of stay (LOS), and their charts were retrospectively reviewed for preoperative, intraoperative, and postoperative factors that were associated with their LOS.

Results: Neuromuscular diagnosis, age at surgery, gender, and the need for tube feeds were not significant predictors of length of stay. Severely involved CP patients were more likely to have extended stays (p=0.02). Major coronal Cobb angle and pelvic obliquity were also significantly higher amongst those with extended stays (p=0.002, p=0.02). Patients with lengthier surgical times, higher numbers of levels fused, presence of a pulmonary complication, need for intraoperative and postoperative blood transfusion, and need for ICU admission were significantly more likely to fall into the extended LOS group (p<0.05).

Conclusions: Several variables have been identified as significant predictors of hospital LOS after PSF for NMS. Further study is needed to identify whether benefit exists to excluding such patients from an AD pathway and whether investing greater resources in optimizing these high risk patients preoperatively with further testing and medical interventions would be of value.

Level of Evidence: Therapeutic Level III

MANUSCRIPT:

Introduction There are multiple reasons why neuromuscular scoliosis (NMS) patients have historically required longer hospital stays after posterior spinal fusion (PSF) than their typically healthy adolescent idiopathic scoliosis (AIS) counterparts. NMS patients have higher rates of comorbidities including seizure disorder, mental retardation, reflux, and reactive airway disease. Many require tube feeds to maintain adequate levels of nutrition or tracheostomies to maintain adequate oxygenation. Those with more involved disease are unable to ambulate. Contractures and spasticity can make hygienic care difficult for their families and caregivers. All of these factors contribute to increased rates of intraoperative and postoperative complications including infection, wound dehiscence, pseudarthrosis, difficulty feeding, urinary tract infection, and respiratory failure. Historic literature cites complication rates as high as 60-70% amongst NMS patients.1-4

Historically, length of stay (LOS) amongst NMS patients has far exceeded LOS cited for AIS patients after PSF. A national database study completed in 2006 assessed 1570 NMS patients who underwent PSF and found mean LOS to be 9.2 days.5 Another national study completed ten years later in 2016 found that, over the course of the study period, which included 2154 NMS patients who underwent PSF, mean LOS declined from 9.1 to 6.7 days.6 Other smaller institutional studies in the past decade cite LOS’s ranging from 8 to 17 days, demonstrating that LOS varies considerably across regions and institutions.7-9

LOS at our institution is shorter than published averages, and an accelerated discharge (AD) pathway was implemented for NMS patients in 2008 which shortened stays further. Prior to 2008, LOS amongst patients with GMFCS 4 or 5 cerebral palsy (CP) averaged 4.9 days, and after 2008 it decreased to 4.0 days.10 In further assessing our NMS population, we found that the majority of patients stayed in the hospital for 3 to 6 days after surgery after implementing the AD pathway; however, a small number of outlier patients had very extended stays in excess of 20 days. These patients skewed our

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mean LOS. We hypothesized that a small subset of NMS patients were not as well-suited for rapid mobilization, early resumption of feeds and discontinuation of drains and catheters as the majority of other patients. By reviewing the charts of NMS patients who underwent PSF, we sought to identify variables that increased risk of extended LOS after surgery, so that these patients might be better optimized and counseled appropriately prior to surgery.

Methods A retrospective chart review was performed for all patients with an underlying neuromuscular diagnosis who underwent posterior spinal fusion by one of two surgeons between the years of 2005 and 2013. This list totaled 233 patients. Patients undergoing revision surgery or placement or adjustment of growth-friendly instrumentation were excluded from this study. Patients who had anterior spinal procedures were also excluded. This left 197 patients who met inclusion criteria.

The patients included in this study encompassed a wide range of neuromuscular diagnoses including but not limited to cerebral palsy (CP), muscular dystrophy, genetic and chromosomal syndromes, spina bifida, Chiari malformations, syrinx, traumatic brain injury, spinal cord injury, spinal muscular atrophy, and Rett syndrome. We assessed patients’ preoperative demographics and comorbidities, as well as feeding and respiratory status. GMFCS level was determined by attending physician and documented in the patient’s preoperative note. Patients with CP were stratified into two groups: less severely involved patients with ambulatory capacity (GMFCS 1-3) and more severely involved patients who were largely unable to ambulate (GMFCS 4-5). Coronal and sagittal Cobb angles and pelvic obliquity were measured on each patient’s non-traction preoperative radiographs.

Next, we reviewed patients’ operative notes, anesthesia documentation, order summaries, and progress notes during their hospital stay to determine estimated blood loss (EBL), surgical time, number of levels fused, presence of intraoperative and postoperative complications, need for transfusion of blood products, need for and length of ICU admission, and hospital length of stay. We also reviewed their postoperative clinic notes for presence of complications and readmissions.

We then divided patients into one of three groups based on their LOS, with patients staying less than 3 days falling into the first quartile, patients staying 3-7 days in the middle two quartiles, and patients staying greater than 7 days falling into the fourth quartile. After stratifying patients into these 3 groups, we analyzed each group to assess for variables that were predictive of LOS group.

Results Roughly half of the patients included in this study were female (56%), and mean age at the time of surgery was 13.2 years. Fifty-three percent of included patients required a feeding tube for nutrition. The majority were stable on room air and did not require supplemental oxygen or tracheostomy prior to surgery. The majority of CP patients were nonambulatory, with 84% rated as GMFCS 4 or 5. Average max coronal Cobb angle was 63 degrees prior to surgery, and mean pelvic obliquity was 17 degrees. Length of surgery and EBL, and postoperative variables are described in Table 2.

Table 1. Baseline patient characteristics Category N (%) or Mean (Std) Age at time of surgery (years) 13.2 (3.2), (n=197) Sex Female 110/197 (56%) Male 87/197 (44%) Feeding status Feeding tube 80/170 (53%) PO 80/170 (47%) Respiratory status Room Air 185/197 (94%) Supplemental O2 7/197 (4%) Tracheostomy Dependent 5/197 (2%) GMFCS (CP only) 1-3 22/136 (16%) 4-5 114/136 (84%) Max cobb angle (deg) 63.4 (18.3), (n=197) Degree of pelvic obliquity (deg) 16.9 (14.6), (n=182)

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Table 2. Admission characteristics N (%) or Mean (Std) EBL 612.1 (486.3), (n=194) Length of surgery 4.3 (1.3), (n=197) Number levels fused 14.5 (2.8), (n=196) Pulmonary complications 29/197 (15%) Required ICU 24/164 (15%) Number of patients required blood transfusion intraop

36/195 (18%)

Units transfused intraoperatively 1.4 (1.2), (n=36) Number of pts requiring blood transfusion postop

29/195 (15%)

Units transfused postop 1.4 (0.8), (n=29)

We found that patients had a median LOS of 4 days, and a mean LOS of 5.4 days. While the vast majority of patients are clustered with length’s of stay from 3-7 days, we found that several significant outliers existed. Of the 197 patients included in our analysis, 6 had stays in excess of 20 days, with the longest stay being 51 days (see Table 3).

Table 3. Distribution of hospital LOS

Most demographic variables were not predictive of hospital LOS. Patients’ type of neuromuscular disease, gender, age at surgery, and dependence on tube feeds for nutrition were not predictive of ultimate LOS. Respiratory status, including the need for supplemental oxygen or tracheostomy prior to surgery, trended toward but did not meet statistical significance (p=0.08).

Several preoperative characteristics, however, did correlate. Patients with more involved CP (GMFCS 4-5) were significantly more likely to fall into the extended stay group, with 90% of CP patients requiring LOS >7 days being severely involved, as compared to 10% of those patients with LOS> 7 days being GMFCS 1-3 (p=0.020). Maximum preoperative coronal Cobb angle was also predictive of LOS, with mean Cobb angle sequentially increasing by LOS group (p=0.002). Preoperative pelvic obliquity also increased sequentially, with a mean angle of 12 deg amongst those patients with LOS <3days as compared to 21 deg amongst those with LOS >7days (p=0.017).

05

1015202530354045

0-2

days

2-3

days

3-4

days

4-5

days

5-6

days

6-7

days

7-8

days

8-9

days

9-10

day

s10

-11

days

11-1

2 da

ys12

-13

days

13-1

4 da

ys14

-15

days

15-1

6 da

ys16

-17

days

17-1

8 da

ys18

-19

days

19-2

0 da

ys20

-21

days

21-2

2 da

ys …39

day

s …51

day

s

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Table 4. Relationship between baseline demographics and LOS groups

A number of intraoperative variables were found to correlate with LOS. Length of surgery was significantly longer in the prolonged LOS group, measuring an average of 1.5 hours longer amongst patients with extended stays than those with short stays (p<0.001). Number of levels fused was also significantly higher amongst the extended LOS group (p<0.001). Those patients who experienced pulmonary complications or required ICU admission were significantly more likely to fall into the extended LOS group. Estimated blood loss (EBL) during surgery trended higher but did not meet statistical significance (p=0.06).

Table 5. Relationship between intraoperative and postoperative variables and LOS groups <3 days 3-7 days >7 days p-value Length of surgery 3.6 (1.2), (n=56) 4.5 (1.1), (n=111) 5.1 (1.6), (n=30) <0.0001 EBL 481.4 (428.5), (n=55) 662.7 (507.8), (n=109) 667.9 (475.7), (n=30) 0.0617 No. Levels Fused 12.9 (3.8), (n-55) 15.1 (2.0), (n=111) 15.3 (1.7), (n=30) <0.0001 Intraop Complications 2/55 (4%) 27/111 (24%) 7/29 (24%) 0.0037 Pulmonary complication 1/56 (25) 16/111 (14%) 12/30 (40%) <0.0001 Required ICU 4/55 (7%) 13/92 (14%) 7/17 (41%) 0.0025 Time in ICU 0.8 (0.5), (n=8) 3.5 (1.7), (n=13) 3.3 (2.0), (n=6) 0.0250 Neurologic deficits 1/56 (2%) 4/111 (4%) 2/30 (7%) 0.4206 Infection, delayed healing 1/55 (2%) 1/95 (1%) 2/22 (9%) 0.1062 Required ABX 2/56 (4%) 9/102 (9%) 3/23 (13%) 0.2476 Required OR 0/53 (0%) 2/106 (2%) 2/26 (8%) 0.0759 Decubitus ulcers 0/56 (0%) 1/110 (1%) 1/25 (4%) 0.3301 Cutout loosening malplacement

0/46 (0%) 2/94 (2%) 0/21 (0%) 1.0000

Bleeding 0/55 (0%) 0/111 (0%) 1/25 (4%) 0.1309 Intraop transfusion 2/55 (4%) 27/111 (24%) 7/29 (24%) 0.0037 Postop transfusion 2/55 (4%) 20/111 (18%) 7/29 (24%) 0.0079 Intraop transfusion units 1.0 (0.0), (n=2) 1.4 (1.4), (n=27) 1.1 (0.4), (n=7) 0.7800 Postop transfusion units 1.0 (0.0), (n=2) 1.3 (0.7), (n=20) 1.7 (1.1), (n=7) 0.4251

<3 days 3-7 days >7 days p-value Age at surgery 13.3 (3.4), (n=56) 13.0 (2.9), (n=111) 13.7 (3.6), (n=30) 0.5642 Sex Female 38/56 (68%) 58/111 (52%) 14/30 (47%) 0.0870 Male 18/56 (32%) 53/111 (48%) 16/30 (53%) Diagnosis Group 1 32/56 (57%) 89/111 (80%) 21/30 (70%) n/a 2 17/56 (30%) 13/111 (12%) 4/30 (13%) 3 0/56 (0%) 1/111 (1%) 1/30 (3%) 4 1/56 (2%) 2/111 (2%) 0/30 (0%) 5 4/56 (7%) 0/111 (0%) 0/30 (0%) 6 0/56 (0%) 3/111 (3%) 2/30 (7%) 7 2/56 (4%) 3/111 (3%) 2/30 (7%) GMFCS Level, cp only 1-3 10/30 (33%) 10/86 (12%) 2/20 (10%) 0.0202 4-5 20/30 (67%) 76/86 (88%) 18/20 (90%) Feeding tube 15/44 (34%) 52/100 (52%) 13/26 (50%) 0.1326 Respiratory status RA 53/56 (95%) 107/111 (96%) 25/30 (83%) 0.0863 Supp O2 2/56 (4%) 2/111 (2%) 3/30 (10%) Trach 1/56 (2%) 2/111 (2%) 2/30 (7%) Max Cobb angle 56.6 (16.9), (n=56) 65.3 (18.8), (n=111) 68.8 (15.6), (n=30) 0.0027 Degree pelvic obliquity 12.6 (14.1), (n=55) 18.0 (13.9), (n=98) 21.3 (16.4), (n=29) 0.0171

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Conclusions Understanding the factors that prolong hospital stay amongst patients with NMS allows physicians to better counsel patients and their families prior to surgery. Patients with more involved CP and patients with more severe curves and pelvic obliquity are more likely to require extended stays. Greater numbers would be needed to determine whether type of neuromuscular diagnosis is also a risk factor. Recent literature cites mean length of stay for patients with spinal muscular atrophy after PSF is as high as 17 days, suggesting that diagnosis may be an important factor, however greater study numbers would be needed to determine the significance of this variable.9

This data begs the question of whether patients with multiple risk factors should be excluded from AD pathways. We have found that that our AD pathway not only shortens LOS but also reduces some complications including pulmonary complications, which have historically been the most prominent complication following PSF for NMS. It is unclear whether delaying mobilization, resumption of feeds, and removal of drains and catheters would benefit these high risk patients. It is equally likely that their risk of prolonged stay and complications would be unchanged if excluded from an AD pathway. Again, further study is needed in this area.

Intraoperative and postoperative findings can also drive hospital stay. Length of surgery, numbers of levels fused, and the need for blood transfusions are all significantly linked to prolonged stays. Pulmonary complications and ICU admission are also significantly more common in the extended stay group. These factors should serve as red flags for those patients who require additional time and resources. Early vigilance and interventions may serve to minimize the complications that drive hospital LOS.

It would also be reasonable to consider whether high risk patients should undergo additional measures preoperatively to optimize them for surgery. For example, formal preoperative pulmonary function testing, respiratory treatments, and preoperative placement of feeding tubes may provide great benefit to a small subset of patients. These measures are not without cost to patients and healthcare centers, but may allow for fewer postoperative issues and improved outcomes. Limiting such interventions to those patients who stand to gain the greatest benefit will focus healthcare dollars and the efforts and time of patients’ families where they matter most.

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References 1. Hasler C. Operative treatment for spinal deformities in cerebral palsy. J Child Orthop. 2013(7):419-423. 2. Fletcher ND, et al. Use of a Novel Pathway for Early Discharge Was Associated With a 48% Shorter Length of Stay

After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis. J Pediatr Orthop. 2015. 3. Jevsevar D, Karlin L. The relationship between preoperative nutritional status and complications after an

operation for scoliosis in patients who have cerebral palsy. J Bone Joint Surg Am. 1993;75:880-884. 4. Barsdorf A, Sproule D, Kaufmann P. Scoliosis surgery in children with neuromuscular disease: findings from the

US National Inpatient Sample, 1997 to 2003. Arch Neurol. 2010;67:231-235. 5. Murphy NA, et al. Spinal Surgery in Children with Idiopathic and Neuromuscular Scoliosis. What’s the Difference?

J Pediatr Orthop. 2006;26(2):216-220. 6. Rumalla K YC, Pugely AJ, Koester L, Dorward IG. Spinal fusion for pediatric neuromuscular scoliosis: national

trends, complications, and in-hospital outcomes. J Neurosurg Spine. 2016;25(4):500-508. 7. Diefenbach C, et al. Hospital Cost Analysis of Neuromuscular Scoliosis Surgery. Bulletin of the Hospital for Joint

Diseases. 2013;71(4):272-277. 8. Beckmann K LT, Gosheger G, Bövingloh AS, Borowski M, Bullmann V, Liljenqvist U, Schulte TL. Surgical correction

of scoliosis in patients with severe cerebral palsy. Eur Spine J. 2016;25(2):506-516. 9. Holt JB DL, Weinstein SL. Outcomes of Primary Posterior spinal Fusion for Scoliosis in Spinal Muscular Atrophy:

Clinical, Radiographic, and Pulmonary Outcomes and Complications. J Pediatr Orthop. 2017;37(8):505-511. 10. Fletcher ND, et al. Use of an accelerated discharge pathway in patients with severe cerebral palsy undergoing

posterior spinal fusion for neuromuscular scoliosis. 2018 (pending publication).

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William Carpenter, MD PGY-5 Adult Reconstruction Fellowship New York University- Insall Scott Kelly (ISK) Institute New York, NY EDUCATION: University of Texas Health Science Center – San Antonio, TX Doctor of Medicine, May 2012 Auburn University Auburn, AL Bachelor of Science, Biomedical Sciences, May 2009

PEER-REVIEWED PUBLICATIONS Gottschalk M, Carpenter W, Hiza E, Reisman W, Roberson J. “Humeral Shaft Fracture Fixation: Incidence Rates and Complications as Reported by American Board of Orthopaedic Surgery Part II Candidates.” JBJS. 2016 Sept 07; 98 (17) e71:1-8 PMID: 27605696

Fletcher N, Sirmon B, Mansour A, Carpenter W, Ward L. “Impact of Insurance Status on Ability to Return for Outpatient Management of Pediatric Supracondylar Humerus Fractures.” Journal of Children’s Orthopaedics. Accepted for publication, August 25th 2016, ahead of print. PMID: 27562575

Carpenter W, Lam D, Toney G, Weintraub N, Qin W. “Zinc, Copper, and Blood Pressure: Human Population Studies.” Medical Science Monitor. 2013; 19:1-8. PMID: 23291705

PENDING PUBLICATIONS

Premkumar A, Gebrelul A, Gottschalk M, Sirmon B, Carpenter W, Roberson J, Erens G, Bradbury T. “Predictors for Delayed Discharge after Total Joint Arthroplasty.”

Carpenter W, Sirmon B, Mansour A, Fletcher N. “Delayed Treatment in Lateral Condyle Fractures.”

Runner R, Carpenter W, Mueller C, Gottschalk M, Seiler J, Roberson J, Wright G, Bradbury T. “How Does Joint Arthroplasty Affect Return to Golf?”

PRESENTATIONS:

Fletcher N, Sirmon B, Mansour A, Carpenter W, Ward L. “Impact of Insurance Status on Ability to Return for Outpatient Management of Pediatric Supracondylar Humerus Fractures.”. Kelly Day, June 2015; Atlanta, GA.

Premkumar A, Gebrelul A, Gottschalk M, Sirmon B, Carpenter W, Roberson J, Erens G, Bradbury T. “Predictors for Delayed Discharge after Total Joint Arthroplasty.” AAOS Annual Meeting, March 2016; Orlando, FL. Georgia Orthopaedic Society Meeting, September 2016

Gottschalk M, Carpenter W, Hiza E, Reisman W, Roberson J. “Humeral Shaft Fracture Fixation: Incidence Rates and Complications as Reported by American Board of Orthopaedic Surgery Part II Candidates.” Kelly Day, June 2016;

BOOK CHAPTERS: Femoral Shaft Fractures. In: The Evaluation of the Orthopaedic Trauma Patient: A Residents Perspective. (In process) Carpenter W, Ahearn B, Reisman W.

Periprosthetic Femur Fractures. In: The Evaluation of the Orthopaedic Trauma Patient: A Residents Perspective. (In process) Runner R, Carpenter W, Shau D, Roberson J.

Clavicle Fractures. In: The Evaluation of Orthopaedic Trauma Patient: A Residents Perspective. (In process) Carpenter W, Ahearn B, Reisman W.

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The Impact Of Socioeconomic Status On Time To Treatment In Pediatric Lateral Condylar Humerus Fractures And The Implications Of Delay In Surgical Treatment On Complications William Carpenter, M.D. , Keith Orland M.D. , Nick Fletcher, M.D. , Allison Spitzer Purpose: The objective of this study was to identify the correlation between delayed surgical treatment and complications in lateral condylar humerus fractures and to identify potential socioeconomic factors contributing to delayed treatment.

Methods: A retrospective review of lateral condylar humerus fractures treated at two large urban pediatric hospitals from 2009-2012 was performed. Fractures were classified according to the Jakob classification and baseline demographics and socioeconomic variables were collected. Time from identification of lateral humeral condyle fractures in the emergency room to surgical fixation was recorded in all patients treated surgically as well as all complications.

Results: 282 lateral humeral condyle fractures were identified, of which 195 received surgical intervention. 40 (20%) of patients received delayed treatment compared with 145 (80%) of patients who received treatment on their first visit. There was no significant difference found between patients who received delayed treatment and socioeconomic factors such as insurance status (p=0.35), language (p=0.09), and distance traveled to the hospital (p=0.40). Overall the delayed treatment cohort developed a higher incidence of complications compared with patients receiving treatment on the first visit (34.5% vs 19.35). Post-operative elbow stiffness was the most common complication identified (10% delayed treatment vs 4.5% first visit) with no significant difference between the two cohorts. Other complications include infection (2.5% vs 1.9%), symptomatic hardware (0% vs 1.3%) and osteonecrosis (8.0% vs 0%) within the delayed treatment and first visit cohort respectively.

Conclusion: There was no identified correlation between socioeconomic factors and delayed treatment. Overall, there was an increased incidence of complications within the delayed treatment cohort with elbow stiffness being the most common.

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Jimmy Daruwalla, MD PGY-5 UPCO FEWSH IP TRAINING:

Hand and Upper Extremity Fellowship Curtis National Hand Center – Union Memorial Hospital Baltimore, MD EDUCATION: Emory University School of Medicine- Atlanta, GA Doctor of Medicine, May 2013 McGill University- Montreal, Quebec Bachelor of Science, Psychology, May 2008

PUBLICATIONS: Seiler III JG, Daruwalla J, Payne S, Faucher GK. Normal palmar anatomy and variations that impact median nerve decompression. J Am Acad Orthop Surg. 2017; 25(9):194-203.

Robins RJ, Daruwalla JH, Gamradt SC, McCarty EC, Dragoo JL, Hancock RE, Guy JA, Cotsonis GA, Xerogeanes JW, ASP Collaborative Group, Tuman JM, Tibone JE, Javernick MA, Tochem EM, Boden SA, Pilato A, Miley JH, Greis PE. Return to play after shoulder instability surgery in National Collegiate Athletic Association division 1 intercollegiate football athletes. Am J Sports Med. 2017; 45(10):2329-2335.

Faucher GK, Daruwalla JH, Seiler III JG. Complications of surgical release of carpal tunnel syndrome: a systematic review. J Surg Orthop Adv. 2017; 26(1):18-24.

Daruwalla JH, Daly CA, Seiler III JG. Medial elbow injuries in the throwing athlete. Hand Clin. 2017; 33(1):47-62. Gottschalk MB, Ghasem A, Todd D, Daruwalla J, Xerogeanes J, Karas S. Posterior shoulder instability: does glenoid retroversion predict recurrence and contralateral instability? Arthroscopy. 2015; 31(3):488-93.

Daruwalla J, Greis P, Hancock R, the ASP Study Group, Xerogeanes J. Rates and determinants of return to play after anterior cruciate ligament reconstruction in division 1 college football athletes: a study of the ACC, SEC, and Pac-12. Orthop J Sports Med. 2014; 2(8):2325967114543901.

Daruwalla J, Sperling L, Nell C, Book W. All in the family? A case of heart failure after pregnancy. J Med Assoc Ga. 2013; 102(3):24-5.

Illei GG, Shirota Y, Yarboro CH, Daruwalla J, Tackey E, Takada K, Fleisher T, Barlow JE, Lipsky PE. Tocilizumab in systemic lupus erythematosus: data on safety, preliminary efficacy, and impact on circulating plasma cells from an open-label phase I dosage-escalation study. Arthritis Rheum. 2010; 62(2):542-552.

GRANTS AWARDED “SDF-1 Release to Prevent Muscle Degeneration in Rotator Cuff Tears.” American Shoulder and Elbow Society 2016

Research Grant; $20,000. Principal Investigator: Dr. Claudius D. Jarrett, MD.

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CURRENT RESEARCH PROJECTS “Cellular Characterization of Rotator Cuff Muscle Atrophy.” Supported by the American Shoulder and Elbow Society

2016 Research Grant. In collaboration with the biomechanical engineering lab of Dr. Johnna Temenoff at The Georgia Institute of Technology. Principal investigator: Dr. Claudius D. Jarrett, MD.

“Surgical Outcomes at an Academic Orthopaedic Surgery Specialty Hospital.” Principal investigator: Dr. Scott Boden, MD. “Perioperative Dexamethasone as Part of a Multi-modal Pain Regiment in Total Knee Arthroplasty.” Principal

investigators: Dr. Thomas Bradbury, MD and Dr. James Roberson, MD

AWARDS & HONORS Resident/Fellow Research Paper Award October, 2017 Eastern Orthopaedic Association Annual Meeting, Miami Beach, FL Thomas E. Whitesides, M.D. Resident Research Award, Third Place October, 2017 Georgia Orthopaedic Society Annual Meeting, Sea Island, GA Delegate to Resident Leadership Forum June, 2017 American Orthopaedic Association, Charlotte, NC Resident Research Award June, 2016

Kelly Society Research Symposium, Emory University School of Medicine

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A University-Based Orthopaedic ‘Focused Factory:’ Does It Provide Better Outcomes? Jimmy Daruwalla, MD, Poonam Dalwadi, BS, Scott D. Boden, MD, Michael B. Gottschalk, MD Abstract Recent publications on specialty hospitals and ‘focused shop’ surgical facilities have reported improved outcomes compared to general, multi-specialty hospitals. However, the validity of these data has been questioned. Specifically, critics claim that these hospitals selectively choose only the healthiest patients and the most straightforward of cases. Additionally, many of these facilities are physician-owned, further introducing potential bias into reported outcomes. Our study sought to clarify this debate by comparing the outcomes of total joint arthroplasty performed at our general university hospital versus when performed at our orthopaedic-dedicated focused facility, which undertakes a high case and patient complexity and is not physician-owned. Our retrospective database study demonstrated a significantly lower rate of periprosthetic joint infection (p = .0059), pulmonary embolism (p = .0001), and myocardial infarction (p = .0003) following total joint arthroplasty performed at our university’s orthopaedic-focused facility compared to our university’s general hospital. We also observed a decreased average length of stay by almost one full day. Rates of DVT were not statistically different between the two facilities (p = .9563). Our data help to support the theory that certain adverse outcomes after total joint arthroplasty are decreased when performed at an orthopaedic-focused hospital versus when done at a general hospital. Our study, based in a university hospital system, also helps to account for potential biases, such as the selective treatment of healthier patients with less complicated pathology, in prior work that demonstrates superior outcomes associated with specialty-focused hospitals. INTRODUCTION

The recent development of surgery specialty hospitals has sparked controversy not only within academic institutions, but also in the political and public realms1-3. Advocates for the development of specialty surgery hospitals claim that these facilities can provide higher quality care in a more efficient manner by focusing available resources on a smaller number of services and procedures. Thus, patients treated in these hospitals may theoretically enjoy better care, comfort, and convenience, all with fewer complications3-4. Opponents say specialty surgery hospitals lead to the overuse of medical care and threaten the welfare of general hospitals5. Specialty hospitals have also been accused of “cherry picking”, i.e. focusing on the most profitable patients by selectively treating those who are well-insured (e.g. not accepting Medicare/Medicaid) and from higher socioeconomic classes. Such a practice would introduce bias into previous data demonstrating improved outcomes in specialty hospitals5-7. More complex and challenging patients may also be referred away from these hospitals, further biasing reported outcomes8-9. Additionally, as many specialty hospitals are physician-owned, potential conflicts of interest that influence practice patterns are also a point of contention5,10. As the United States’ health care system struggles to balance access to care, quality, and cost, the debate on the utility of specialty surgery hospitals is more relevant than ever.

Nevertheless, the impact of specialty surgery hospitals on the quality, efficiency, and cost of delivering surgical health care is largely unknown. Moreover, very few studies have assessed outcomes in specialty orthopaedic hospitals, the largest category of specialty hospitals11. In one study, there was a 40% decreased risk of adverse outcomes after total hip or knee arthroplasty when performed in specialty hospitals compared to general hospitals8. Another study demonstrated that, as the degree of orthopaedic specialization increased across hospitals, the odds of adverse outcomes decreased progressively4. While these studies present promising data on the potential benefit of specialty surgery hospitals, they include data from many private,

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physician-owned orthopaedic specialty hospitals that are susceptible to the potential biases outlined above. As such, these studies do little to refute the arguments that certain confounders, such as the selective admission of healthier and well-insured patients, have a significant impact on the results. In fact, Cram et al. found that patients undergoing surgery at orthopaedic specialty hospitals had fewer comorbid medical conditions and were more likely to live in areas with higher home values and per capita incomes8, supporting the criticism that specialty hospitals demonstrate better outcomes in part by selectively treating healthier and better-insured patients. Interestingly, no academic or university specialty hospitals were included in this analysis.

To date, no study has compared the outcomes of orthopaedic procedures performed at a university-based general versus orthopaedic-focused hospitals. Thus, the purpose of our study is to compare the rates of adverse outcomes and length of stay (LOS) following total hip and knee arthroplasty when performed at our orthopaedics hospital versus when performed at our general university hospital. We believe that comparative outcomes data from our university-based orthopaedics hospital would be uniquely suited to address the potential biases from prior studies on specialty hospitals, since patients with all insurance payers, including Medicare and Medicaid are treated. Furthermore, as the hospital is part of the university system, physician ownership is also not a potential bias. Finally, our university-based orthopaedic hospital is a tertiary- and even quaternary-referral center, where case complexity is often extremely high; a multitude of challenging, revision procedures are performed regularly. An increased case complexity, and therefore complication rate, is a well-accepted characteristic of academic teaching hospitals. In fact, recent changes to the payment system by the Centers for Medicare and Medicaid Services (CMS) have increased reimbursements to teaching hospitals since these facilities generally admit more severely ill patients.

We hypothesize that patient outcomes after total hip and knee arthroplasty will be improved in patients undergoing surgery at our orthopaedic-focused hospital versus those patients undergoing the same surgeries at our general university hospital. This data will lend support to the argument that the improved outcomes associated with specialty orthopaedic hospitals are due to the inherent benefits of hospital specialization and independent of factors like case complexity and patients’ insurance type.

METHODS Participant Selection

After Institutional Review Board approval of this retrospective cohort study, we identified all patients who underwent a primary or revision total hip or knee arthroplasty at our university’s orthopaedics and spine hospital from September, 2008 (the date the hospital opened) through October, 2012. We also identified patients undergoing the same procedures at our university’s general hospital until August, 2008 (when our service moved to the specialty hospital). Data collection from the general hospital was started from January, 2004, in order to collect data over the same length of time from both hospitals. Patients were identified from the Emory University Information Technology Medical Coding database with the use of the Current Procedural Terminology (CPT) codes and International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes. The medical records of these patients were reviewed for the outcome measures of interest (listed below), again using CPT and ICD-9-CM codes, which can be pulled using the data warehouse. Outcome Measures and Control Data

Our primary outcome measures are a set of postoperative complications, including periprosthetic infection, pulmonary embolism (PE), deep vein thrombosis (DVT), and myocardial infarction (MI). We also reported on length of stay (LOS). All events were considered complications if they happened within 90 days after surgery, with the exception periprosthetic infection, for which there was no time limit.

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The same surgeons performed all procedures at both hospitals. Thus, to serve as a control for other factors that may account for an improvement in outcomes besides the transition from a general to specialty hospital, such as increasing surgeon experience, we also collected the same data from another general university hospital within our academic system from January 1, 2004 to October, 2012 and assessed for a trend in the same outcome measures over this time. Using publicly-available data on the internet, we obtained the case mix index (CMI) for other academic and private hospitals in our city and state so that we could compare the relative case complexity of our hospital to regional norms. Statistical Analysis The incidence of each postoperative complication was calculated for the two hospitals being compared. Differences between the outcomes of patients in the orthopaedic specialty hospital and those in the general hospital were compared with the use of Chi Square Analaysis (N > 10 frequency) and Fisher’s exact test (N < 10 frequency). JMP Pro 12 (Cary, NC) was used to calculate the statistics. RESULTS

Within our data collection period, a total of 7461 total hip or knee arthroplasty procedures, including primary and revision cases, were performed. 3704 total hip or knee arthroplasty procedures were performed at our university specialty hospital and 3757 procedures were performed at our general hospital.

Periprosthetic joint infection occurred in 0.60% of patients at the orthopaedics hospital, compared to 1.3% of patients at the general hospital (p = .0059). PE occurred in 5 (0.13%) patients at the specialty hospital and in 26 (0.69%) at the general hospital (p = 0.0001). DVT occurred in 33 (0.89%) patients at the orthopaedics hospital, compared to 22 (0.59%) at the general hospital (p = 0.9536). Finally, we observed 8 (0.22%) MIs in patients at the orthopaedics hospital versus 30 (0.80%) patients at the general hospital (p = 0.0003). Length of stay significantly reduced from an average of 3.55 days at the general hospital to 2.34 days at our orthopaedics hospital.

Data from a second, ancillary general university hospital was analyzed as a control to show that time alone (a surrogate for surgeon experience) did not account for an improvement in outcomes in our data. We saw no difference in adverse outcomes following total joint arthroplasty performed before versus after September, 2008 (the time when our orthopaedics service moved from the main general hospital to the orthopaedics hospital). Specifically, there was no difference in the frequency of periprosthetic joint infection (p = 0.7868), PE (p = 0.8011), or DVT (p = 1.000).

Average CMI for our university-based orthopaedics hospital was 2.8203. The average CMI for a sample of hospitals in our metro area outside of our university system was 2.6162 (range: 2.4993–2.7853). When parsing out our average CMI data by payer type, CMI for patients with private insurance was 2.1777, while CMI for patients covered by CMS was 2.253. DISCUSSION As hypothesized, we demonstrate that the incidence of several major adverse outcomes following total joint arthroplasty is lower when performed at an orthopaedics specialty hospital than when performed at a general hospital. Specifically, we found significantly lower rates of periprosthetic infection (p = .0059), PE (p = 0.0001), and MI (p = 0.0003). We also demonstrated a lower average length of stay by more than one full day. Given the devastating nature of infections in the setting of total joint arthroplasty, we are very encouraged by these findings, which reflect what we have observed anecdotally since transitioning the arthroplasty service to the orthopaedics specialty hospital.

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In a climate of increasing healthcare costs and a focus on evidence-based therapies, efforts to find value in our healthcare practices are more critical than ever. As such, the development of specialty hospitals was designed to streamline and expedite patient care, thereby improving outcomes. However, despite a rise in the number of these facilities in operation, published literature validating their efficacy is relatively sparse. Furthermore, the existing data that does support specialty hospitals has been criticized, mostly pertaining to biases in patient selection. Thus, our study was designed to investigate the potential efficacy of an orthopaedic specialty hospital in improving postoperative outcomes while attempting to control for these biases. As a university based orthopaedic specialty hospital that serves as a tertiary and quaternary referral center for much of the southeastern United States, case complexity and patient comorbidity is higher than average. Accordingly, we observed a higher CMI (2.8203) in our university-based orthopaedic specialty hospital compared to all other local and regional hospitals outside of our university system for which data was publically available (average = 2.6162). Thus, our 90-day complication and CMI data support the claim that, even in the setting of increased case complexity, our transition to a dedicated orthopaedic specialty hospital resulted in a lower rate of complications. This was observed all while also enjoying a shorted average length of stay.

Most likely, the decrease in adverse postoperative outcomes and improvements in LOS observed in this study is the multifactorial, cumulative effect of many policies and interventions delivered in a team-based approach. The delivery of such a coordinated and cooperative approach to healthcare is facilitated by specialty hospitals, where a narrower scope of practice allows providers and ancillary staff to focus on more targeted tasks to improve care. For example, it is possible that the initiation of physical therapy on postoperative day zero may have contributed to the lower incidence of PE and shorted LOS observed in our study. Rarely occurring at our general hospital, it is commonplace at our orthopaedics hospital for patients to get out of bed on postoperative day zero with their therapists, who are more comfortable and attuned to arthroplasty-specific protocols and patients. Similarly, possible explanations for a decrease in infection rate seen at our orthopaedics hospital include shorter operative times and/or a concerted focus on pre-, intra-, and post-operative prophylaxis techniques, though our study is not designed to answer these theories.

No significant difference (p = .9536) in the rate of postoperative DVT was observed. We hypothesize that the occurrence of a DVT is perhaps mostly related to factors intrinsic to a patient’s physiology rather than the implementation of various prophylactic measures. Thus, hospital factors may not have as much of an influence on its incidence. It is important to note that our pharmacologic prophylaxis protocol did not change after the transition from our general hospital to the orthopaedics hospital. The same surgeons who were performing total hip and knee arthroplasties at our general hospitals performed the surgeries studied at our orthopaedics hospital. This helps exclude a potential confounding variable from our data. To help demonstrate that increasing surgeon experience over time did not account for the decrease in postoperative adverse outcomes, we studied the trend in these same outcomes at a different general university hospital over the same time period. We saw no difference in the rate of infection, DVT, PE, or sepsis over time at this hospital. These data help support the theory that the improvement in outcomes observed at our specialty hospital are likely not due to improvement in surgeon technique over time. Several limitations of our study design and data are worth noting. Firstly, it is a retrospective, database study and thus susceptible to several inherent biases that cannot be controlled for. As a database study, we assume that all CPT/ICD-9 codes were entered accurately, though variation in documentation can easily result in under- or over-reporting of complications. Future studies should aim to prospectively collect such data, as well as obtaining patient reported clinical outcome measures.

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CONCLUSION Our data help to support the theory that adverse outcomes after total joint arthroplasty are decreased when the procedure is performed at an orthopaedic-focused hospital versus when done at a general hospital. Our study, based in a university hospital system, also helps to eliminate potential biases, such as the selective treatment of healthier patients with less complicated pathology, from prior work that demonstrate superior outcomes associated with specialty hospitals. REFERENCES

1. Iglehart J. “The emergence of physician-owned specialty hospitals.” NEJM. 2005; 325:78-85. 2. Voelker R. “Specialty hospitals generate revenue and controversy.” JAMA. 2003; 284:409-410. 3. Casalino LP, Devers KJ, Brewster L. “Focused factories? Physician-owned specialty facilities.” Health Affairs.

2003; 22:56-67. 4. Hagen T, Vaughan-Sarrazin M, Cram P. “Relation between hospital orthopaedic specialization and

outcomes in patients aged 65 and older: retrospective analysis of US Medicare data.” BMJ. 2010; 340:165-173.

5. Heard DN. “The specialty hospital debate: The difficulty of promoting fair competition without stifling efficiency.” Houston Journal of Health Law and Policy. 2005; 6:215-243.

6. Barker D, Rosenthal G, Cram P. “Simultaneous relationships between procedure volume and mortality: Do they bias studies of mortality at specialty hospitals?” Health Economics. 2011; 20:505-518.

7. Kahn C. “Intolerable risk, irreparable harm: The legacy of physician-owned specialty hospitals.” Health Affairs. 2006; 25:130-133.

8. Cram P, Vaughan-Sarrazin M, Wolf B, Katz J, Rosenthal G. “A comparison of total hip and knee replacement in specialty and general hospitals.” JBJS. 2007; 89:1675-1684.

9. Koval K, Tingey C, Spratt K. “Are patients being transferred to level-1 trauma centers for reasons other than medical necessity?” JBJS. 2006; 88: 2124-2132.

10. Mitchell J. “Effect of physician ownership of specialty hospitals and ambulatory surgery centers on frequency of use of outpatient orthopedic surgery.” Arch Surg. 2010; 145:732-738.

11. Specialty Hospitals: information on national market share, physician ownership and patients served. GAO-03-683R. Washington, DC: United States General Accounting Office; 2003:1-20. http://www.gao.gov/new.items/d03683r.pdf. Accessed 2012 Jul 15.

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Anuj Patel, MD PGY-5 Administrative Chief Resident

UPCOMING FELLOWSHIP TRAINING: Spine Surgery Fellowship Harvard University Department of Orthopaedic Surgery Hartford, CT EDUCATION: University of South Alabama College of Medicine Mobile, AL Doctor of Medicine, May 2013 Georgetown University, Washington, DC Bachelor of Science, ACS Accreditation in Biology, May 2009

PUBLICATIONS Rhee J, Shi J, Cyriac M, Kim J, Zhou F, Easley K, Patel A. The P-mJOA: A Patient-derived, Self-reported Outcome Instrument for Evaluating Cervical Myelopathy: Comparison with the mJOA. Clin Spine Surg. 2018; 31(2): E115-E120. PMID 29088009 • Winner of Best Clinical Abstract, CSRS, 2016.

Patel A, Vu C, Shi J, Robertson D, Gottschalk M, Rhee J. Risk factors of Lumbar Spinal Epidural Lipomatosis. Manuscript submitted for publication Jan 2018.

Patel A, Runner R, Bellamy JT, Rhee J. A Novel Localization Technique for Lumbar Spine Surgery. Manuscript pending submission for publication.

Patel A, Roberson D, Walker M, Younan Y, Vu C, Gottschalk M, Rhee J. Lumbar Spinal Epidural Lipomatosis: MRI Quantification and association with Risk Factors. Manuscript submitted for publication May 2017

Patel A, Thakur N, Heller J. C1-C2 arthrodesis: A Comparison of Cost and Radiographic Outcomes between the Magerl and Goel-Harms Techniques. Manuscript pending submission for publication.

Segal D, Grabel Z, Patel A. Biomechanical Analysis of Cervical Disk Arthroplasty Adjacent to a Multi-level Cervical Anterior Fusion. Awarded Emory Orthopaedics Seed Grant - July 2016.

PRESENTATIONS The Pa-Mjoa: A Patient-Derived, Self Reported Outcome Instrument For Measuring Myelopathy - Comparison With The Mjoa CSRS Annual Meeting Toronto ,Canada December, 2016

Risk factors of Lumbar Spinal Epidural Lipomatosis. NASS Annual Meeting Orlando, FL October, 2017; SOA Annual Meeting, Hilton Head, SC June, 2017

Observed Patterns of Cervical Radiculopathy: How often do they differ from standard distribution? NASS Annual Meeting Orlando, FL October, 2017

Lumbar Spinal Epidural Lipomatosis: MRI Quantification and association with Risk Factors. Society for Skeletal Radiology Annual Meeting San Diego, CA March, 2017 ; Orthopaedic Research Society Annual Meeting San Diego, CA March, 2017

Risk factors of Lumbar Spinal Epidural Lipomatosis. Kelly Day Atlanta, GA June, 2016

Open Reduction Internal Fixation with Primary Total Hip Arthroplasty for Posterior Column Posterior Wall Acetabular Fracture. - Atlanta Trauma Symposium Atlanta, GA May, 2015

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A Reproducible And Reliable Localization Technique For Lumbar Spine Surgery That Minimizes Unintended-Level Exposure And Wrong-Level Surgery Anuj Patel, MD, Robert P. Runner, MD, Poonam Dalwadi, BS, Matthew Pombo, MD, Kyle Hammond, MD Study Coordinators: Patricia Bush Ed.D BACKGROUND CONTEXT: Exposure of unintended levels (defined as a spinal segment outside the intended surgical levels) is unnecessary and potentially adds to operative time and patient morbidity. Wrong-level surgery (defined as decompression, instrumentation, or fusion of a spinal segment not part of the intended surgical procedure) clearly adds to morbidity as well as putting the surgeon at medicolegal risk. PURPOSE: To describe a localization technique for posterior lumbar spine surgery to minimize both unintended-level exposure and wrong-level surgery. STUDY DESIGN: Consecutive case series PATIENT SAMPLE: 1,986 consecutive posterior thoracolumbar operations performed from January 2010 to January 2017 using this technique were reviewed. OUTCOME MEASURES: The primary outcome measure was the incidence of unintended-level exposure and wrong-level surgery. METHODS: This localization technique was consistently used for determination of skin incision, soft tissue dissection, and identification of spinal levels for all patients undergoing posterior lumbar surgery during the time interval noted. Two spinal needles are inserted under sterile technique 3cm lateral to the midline prior to incision at the approximate cranial and caudal aspects of the anticipated incision based on external landmarks. A cross-table lateral x-ray prior to incision is obtained and the actual incision is adjusted based on the location of the spinal needles. Once dissection is carried down to the facet capsules, spinal needles are then placed in adjacent facets and a second cross-table lateral film is obtained to confirm appropriate levels. A retrospective review of all posterior lumbar cases was performed to determine the incidence of unintended-level exposure and wrong-level surgery using this technique. RESULTS: There were no wrong-level surgeries during this time period. There were 6 (0.30%) cases of unintended-level exposure. CONCLUSIONS: The technique described provides surgeons with a reliable, accurate, and easily reproducible method for localizing surgical levels during posterior lumbar spine surgery while minimizing exposure of uninvolved areas. This technique offers distinct advantages over previously proposed protocols and may lead to a widely accepted system for intraoperative spinal level identification. KEY WORDS: Wrong-level surgery, incorrect-site surgery, posterior lumbar spine surgery, localization, novel technique, complication, exposure INTRODUCTION: Current spine literature reflects a heterogeneous grouping of intraoperative protocols to identify the correct surgical level in posterior lumbar spine surgery.1-5 In addition, Mody et al has shown that there is variable use of these protocols within the spine surgery community.6 These variable and potentially unreliable techniques

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can result in incorrect spinal level localization which puts surgeons at risk of two main complications: exposure of an unintended spinal level during dissection and wrong-level decompression or instrumentation. A recent systematic review by Devine et al listed the incidence of wrong-level spine surgeries in the literature ranging from 0.09 to 4.5 per 10,000 surgeries.7 Such an error can have a social and emotional impact on the patient-doctor relationship as well as serious medicolegal implications.11, 12 More importantly, wrong-level surgery may fail to address the patient’s symptoms for which they pursued operative treatment in the first place. Unintended-level exposure, in which a surgeon dissects down to a spinal level that was not part of the original surgical plan, has been reported to occur in anywhere from 1.3 to 15% of cases.8, 9 Though exposing an unintended level can be corrected intraoperatively and is distinct from wrong-level surgery, unintended-level exposure in itself carries potential morbidity including increased length of incision, increased operative time, and greater soft tissue dissection. Additionally, exposing or dissecting the wrong facet capsule could potentially lead to additional levels requiring fusion or earlier onset of adjacent level degeneration. The continued incidence of wrong-level surgeries makes the lack of a nationally recognized standard for proper level identification among spine surgeons concerning. We present a detailed description of an efficient localization technique and its results when used in posterior lumbar spine surgery (both decompressions and fusions). Our goal is to devise a reliable standard for proper level identification and thereby minimize unintended-level lumbar spine exposure and eliminate wrong-level surgery. MATERIALS AND METHODS: Localization Technique A standard method for localization was used for all patients that underwent a posterior lumbar spine surgery (both decompressions and fusions) since the method was initiated in January 2010. Patients are positioned prone on the operating room table. Preoperative imaging is printed, hung in the rooms, and visible to all staff. The correct levels for the consented surgery are clearly identified and marked by the attending surgeon on anterior-posterior and lateral radiographs as well as sagittal magnetic resonance imaging (MRI) cuts. The planned skin incision is also marked on the preoperative lateral radiograph. In accordance with World Health Organization (WHO) procedures, the circulating nurse initiates a time-out procedure prior to incision which allows all providers in the room to introduce themselves and confirms the patient’s name, medical record number, procedure, and surgical site, including spinal level and side that is indicated on the patient’s consent form.13 The patient’s lumbar skin is then disinfected and prepped with DuraPrep™ surgical solution (3M™, St Paul, MN) in the standard fashion. Based on external anatomic landmarks such as the top of the iliac crest, two spinal needles are then inserted using sterile gloves through the skin into the paraspinal muscles (Figure 1). These needles are directed exactly perpendicular to the floor - approximately 3 cm lateral to the spinous processes to avoid inadvertent dural puncture – and placed at the levels corresponding to the estimated proximal and distal extents of the skin incision desired for the given operation. A cross-table lateral radiograph is then taken with the two needles in place prior to draping (Figure 2). The image is reviewed and printed for the room, confirming both spinal needles, sacrum, and indicated surgical levels are visible in the image. The estimated cranial and caudal aspects for an appropriate skin incision are then marked on the lateral radiograph image prior to draping (Figure 3). The patient is then draped in standard sterile fashion. The location of the needles is marked with a line perpendicular to the spine (Figure 4) prior to removing the needles and covering the surgical site with Ioban™ (3M™, St. Paul, MN). Based on the location of the needles on the cross-table image, we then determine or adjust the exact skin incision that corresponds to the proposed incision that was marked on the lateral radiograph preoperatively (Figure 5). The skin is incised and dissection is then carried down through fascia to the facets of interest, leaving the facet capsule completely intact. On one side (i.e., either left or right),

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a spinal needle is then placed superficially in one or two facet joints. One needle is sufficient for a one level decompressive procedure; two consecutive needles are placed for multilevel decompressions or when performing one or more level fusions. This time, the needles are ideally placed parallel to the corresponding disc space, so that on imaging the needles will “point” to the operative level(s) of interest. A second cross-table lateral radiograph is then taken to include both needles in the facet joints, the sacrum, and the indicated surgical spinal levels. The correct level in the lumbar spine is then confirmed by identifying the facet joints in which the spinal needles are placed. The facet joints are then clearly marked with a surgical pen, the spinal needles are removed, and the case proceeds for exposure, decompression and/or instrumentation. Methods After obtaining approval from the institutional review board all patients who underwent posterior lumbar or thoracolumbar decompression or instrumentation by a single surgeon at an academic institution between January 1, 2010 and January 1, 2017 were identified by ICD-9-CM and CPT codes. We excluded patients who did not have a cross-table lateral radiograph of the spinal needles in the facet capsule available for review in the medical record, likely due to errors in saving the images. Medical charts were reviewed for patient demographics (age, gender) and operative plan. The intraoperative cross-table lateral radiographs were reviewed to determine the incidence of unintended-level exposure. A correct level exposure was defined by at least one needle being in an appropriate facet capsule given the intended operative plan (Figure 6). An unintended-level exposure was defined by no spinal needles placed into appropriate facet capsules for the operative plan (Figure 7). Routine postoperative upright anterior-posterior and lateral radiographs of the lumbar spine were obtained on all instrumented patients after mobilization with physical therapy and prior to discharge in order to verify treatment of the correct spinal level. Patients who underwent decompression without instrumentation had postoperative radiographs at the 6-week follow up while fusion procedures had a minimum of 6-month radiographs. The respective postoperative imaging for every patient was reviewed and compared to the original procedure description in the operative report in order to determine the incidence of wrong-level surgery. A wrong-level surgery was defined as decompression, instrumentation, or fusion at a level not designated in the procedure description section of the operative report. RESULTS: 2,073 posterior lumbar or thoracolumbar operations using the technique described qualified for inclusion in this study. Of these, 87 cases did not have a cross-table lateral radiograph saved into the online viewing system and were excluded from the study. There were 1,986 cases included in the final analysis. The surgically treated levels were as follows: T2 in 1 procedure, T3 in 4 procedures, T4 in 9 procedures, T5 in 9 procedures, T6 in 10 procedures, T7 in 10 procedures, T8 in 11 procedures, T9 in 14 procedures, T10 in 50 procedures, T11 in 64 procedures, T12 in 76 procedures, L1 in 137 procedures, L2 in 447 procedures, L3 in 914 procedures, L4 in 1620 procedures, L5 in 1789 procedures, and S1 in 735 procedures (Figure 8). There were 6 (0.30%) cases in which no facet-level spinal needle was at the intended operative level, indicating unintended-level exposure. There were zero wrong-level decompressions or instrumentations during this time period as determined by the postoperative radiographs. All 1,986 patients had postoperative radiographs that confirmed the correct levels – none were lost to follow up in that regard. DISCUSSION: Wrong-level spine surgery is a relatively rare occurrence but can be more difficult to prevent than wrong-site surgeries in other surgical fields. Especially in the setting of increased body mass, transitional lumbar vertebral segments, severe spondylosis or deformity, and revision lumbar operations, identifying the appropriate surgical

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level is seemingly straightforward but in actual practice can at times be very challenging. Our goal is for the proposed protocol to serve as a reliable and easily reproducible method of level localization that will improve upon the protocols described below, namely in its ability to minimize unintended-level exposure and wrong-level surgery. Using this technique, the occurrence of unintended-level surgery was 0.3% and that of wrong-level surgery was 0%. Comparison to Other Protocols There have been several previously proposed protocols to address the issue of wrong-level and wrong-side spine surgeries; however, we believe that our novel technique offers distinct advantages. Mitchell et al proposed the “knife check strategy,” where the scrub nurse verifies the surgical site with the surgeon just prior to incision.4 Jhawar et al suggested the use of the “ABCD pause” method, which involves a pre-incision review of the operative schedule and diagnostic imaging by the entire surgical team.3 Notably, this time-out does not address the issue of wrong-level error. The Joint Commission on the Accreditation of Healthcare Organizations (JCAHO) instituted a universal surgical protocol consisting of a three-step process where the operative plan is verified with the patient preoperatively, the operative site is marked, and a surgical time-out is executed prior to starting the procedure.2 While these protocols have been effective in outlining the importance of preoperative site verification, none of them incorporate the use of intraoperative radiography, which is obviously essential in the setting of spine surgery in order to verify not only the correct region (i.e. the posterior lumbar spine), but also the correct level(s) (eg. L4-L5). Ebraheim et al demonstrated that reliance solely on palpation of anatomic landmarks is an unreliable method for level identification in posterior lumbar spine surgeries.14 The use of anatomic landmarks is only further complicated when operating on obese patients. The importance of incorporating intraoperative imaging for localization of the correct level in spine surgery has been recognized by several studies.9, 15-17 Ammerman et al found a 15% incidence of wrong-level exposure in the lumbar spine without the use of confirmatory radiograph.8 Some protocols exist that integrate the use of intraoperative imaging. Wong et al established the “Sign, Mark, and X-ray” program, shortened to SMaX. This protocol consists of signing the surgical site preoperatively, marking the level with a radiopaque marker, and confirming the correct level with a radiograph of the spine with the marker in place. A comprehensive surgical time-out is also included.1 In 2010, Irace et al proposed the IRACE method, which incorporates components of both the SMaX program and the “knife check strategy.” In this method, a wire is placed in the cranial spinous process of the appropriate spinal level and lateral fluoroscopy is used to confirm the correct level. Following confirmation, the superficial aspect of the wire is cut and a surgical time-out process is employed in which the level and side of the procedure are verified. Additional fluoroscopic confirmation is only utilized in cases of challenging anatomy or when a subtotal arthrectomy is planned.5 When comparing the technique proposed in this paper with the aforementioned protocols, we believe that our technique offers several advantages. First, we recognize the importance of the detailed surgical time-out process and encourage the use of a refined method similar to the WHO Surgical Safety Checklist or the one proposed by Irace et al.5, 13 Our technique focuses upon improvement of intraoperative spinal level confirmation via the use of intraoperative imaging. Our technique utilizes lateral radiographic confirmation using spinal needles as radiopaque markers at both the level of the skin and the facet joints, as opposed to the IRACE method, which only uses routine fluoroscopic imaging at the level of the skin. Our protocol serves as a second line of defense against wrong-level error. It also avoids the potential complications involved in using a buried wire as a guide for dissection as described in the IRACE method, which include mobilization of the wire during dissection and unintentional retention of the wire postoperatively. The 0% incidence of wrong-level surgeries across the 1,986 posterior lumbar spine cases performed in this study demonstrates the efficacy and reliability of this technique for spinal level localization. Additionally, this technique does not add to intraoperative time. The spinal needles can be inserted in a few seconds and the cross-table lateral radiograph

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can be obtained while the surgeons are scrubbing. The use of cross-table radiographs rather than C-arm fluoroscopy allows for more detailed evaluation of bony structures for a clearer interpretation of levels and comparison to preoperative radiographs. In fact, although beyond the scope of this study, we believe that this method may actually save operative time, because the first radiograph guides the skin incision and therefore time is not wasted exposing unnecessary levels. Our method specifically avoids marking or considering the spinous processes, which we believe is a major cause of improper interpretation of level. For lumbar surgery, we believe that a marker on the facet is preferable to the spinous process for the following reasons. First, the facet complex represents the motion segment being operated upon and is co-linear with the disc, making it easy to verify the surgical level on a lateral x-ray. In addition, because the facet is immediately adjacent to the pedicle, marking the facet makes it easy to identify the pedicle being instrumented. In contrast, because the spinous process extends distally from its origin to overlap the lamina caudal to it, it is generally not co-linear with the motion segment being operated upon and has no reliable relationship to the pedicle, facet, or disc on a lateral x-ray. This variability in the relationship between the spinous process with the disc, facets, and pedicles can lead to confusion in interpreting intraoperative lateral x-rays, especially in the setting of severe degenerative changes or scoliosis. Second, the spinous process is often not well visualized on portable intraoperative x-rays, especially in larger patients, whereas the facets and discs are almost always radiographically visible. An additional potential benefit to the proposed technique is the preoperative determination of approximate proximal and distal extent of the skin incision. The routine employment of two spinal needles to define these boundaries helps to guide dissection down to the desired levels, thereby decreasing the incidence of unintended-level exposure. The current study reports a 0.30% incidence of unintended-level exposure compared to the reported values ranging from 1.3 to 15% in other studies.8, 9 When analyzing the 6 cases of unintended-level exposure, we found that only one facet-level needle was used in 4 of the cases. Inherently, using only one needle to localize the operative levels will be less accurate than using two. If these cases in which only one facet-level needle was used are excluded, the incidence of wrong-level exposure decreases to 0.1%. Therefore, we recommend the use of two facet-level spinal needles in every case with the exception of single-level decompression procedures in which only one level needs to be exposed. In another case of unintended-level exposure, the patient was obese with a BMI of 38 kg/m2, making the interpretation of imaging considerably more difficult. In all of these cases, the protocol allowed the surgeon to identify and correct the unintended-level exposure before going on to decompress or instrument the intended spinal levels. The reproducibility of any proposed protocol is a necessary consideration. This series was carried out at an academic center, and the localizations were performed by a combination of junior residents, senior residents, fellows, and the single attending. We feel that the low wrong-level surgery and unintended-level exposure rates demonstrate the efficacy of this localization protocol when utilized by surgeons at any level of experience. In a survey by Groff et al, to all of the members of the Joint Section on Disorders of the Spine and Peripheral Nerves, 88.6% of surgeons answered that they had exposed the wrong level at some point in their career.18 Even if correctable intraoperatively, exposure of the wrong site can lead to increased operative time, incision length, and soft tissue injury. The proper determination of the proximal and distal extent of the skin incision prior to any deep dissection decreases the size of the skin incision and also soft tissue injury. By establishing a reliable, reproducible, and efficient technique for spinal intraoperative level identification, we have been able to avoid unintended-level dissections and minimize the incidence of associated complications. CONCLUSIONS: Unintended-level exposure and wrong-level surgery continue to occur despite adherence to current national guidelines. This study shows that our technique of localization is associated with a very low rate of unintended-level exposure and no wrong-level surgeries in a large series of posterior thoraco-lumbar operations.

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REFERENCES: 1. Wong DA, Watters WC. To err is human: quality and safety issues in spine care. Spine (Phila Pa 1976) 2007;32:S2-8. 2. Joint Commision on the Accreditation of Healthcare Organizations (USA): Universal Protocol. 2004. Available at: http://www.jointcommision.org/PatientSafety/NationalPatientSafety-Goals/04_npsgs.htm. Accessed May 2017. 3. Jhawar BS, Mitsis D, Duggal N. Wrong-sided and wrong-level neurosurgery: a national survey. J Neurosurg Spine 2007;7:467-472. 4. Mitchell P, Nicholson CL, Jenkins A. Side errors in neurosurgery. Acta Neurochir 2006;148:1289-1292. 5. Irace C, Corona C. How to avoid wrong-level and wrong-side errors in lumbar microdiscectomy. J Neurosurg Spine 2010;12:660-665. 6. Mody MG, Nourbakhsh A, Stahl DL, et al. The prevalence of wrong level surgery among spine surgeons. Spine (Phila Pa 1976) 2008;33:194-198. 7. Devine J, Chutkan N, Norvell DC, et al. Avoiding wrong site surgery: a systematic review. Spine (Phila Pa 1976) 2010;35:S28-36. 8. Ammerman JM, Ammerman MD, Dambrosia J, et al. A prospective evaluation of the role for intraoperative x-ray in lumbar discectomy. Predictors of incorrect level exposure. Surg Neurol 2006;66:470-474. 9. Wiese M, Kramer J, Bernsmann K, et al. The related outcome and complication rate in primary lumbar microscopic disc surgery depending on the surgeon's experience: comparative studies. Spine J 2004;4:550-556. 10. Patient safety first alert--implementing a correct site surgery policy and procedure. AORN J 2002;76:785-788. 11. Fager CA. Malpractice issues in neurological surgery. Surg Neurol 2006;65:416-421. 12. Goodkin R, Laska LL. Wrong disc space level surgery: medicolegal implications. Surg Neurol 2004;61:323-342. 13. World Alliance for Patient Safety. WHO Surgical Safety Checklist. 2008. Available at: http://www.who.int/patientsafety/safesurgery/ss_checklist/en/. Accessed May 2017. 14. Ebraheim NA, Inzerillo C, Xu R. Are anatomic landmarks reliable in determination of fusion level in posterolateral lumbar fusion? Spine (Phila Pa 1976) 1999;24:973-974. 15. Clarke JR, Johnston J, Blanco M, et al. Wrong-site surgery: can we prevent it? Adv Surg 2008;42:13-31. 16. Maroon JC, Abla AA. Microlumbar discectomy. Clin Neurosurg 1986;33:407-417. 17. Pao JL, Chen WC, Chen PQ. Clinical outcomes of microendoscopic decompressive laminotomy for degenerative lumbar spinal stenosis. Eur Spine J 2009;18:672-678. 18. Groff MW, Heller JE, Potts EA, et al. A survey-based study of wrong-level lumbar spine surgery: the scope of the problem and current practices in place to help avoid these errors. World Neurosurg 2013;79:585-592. 19. Roberts MP. Lumbar disc herniation. Standard approach. Neurosurg Clin N Am 1993;4:91-99. 20. Barrios C, Ahmed M, Arrotegui J, et al. Microsurgery versus standard removal of the herniated lumbar disc. A 3-year comparison in 150 cases. Acta Orthop Scand 1990;61:399-403. 21. Boruk M, Chernobilsky B, Rosenfeld RM, et al. Age as a prognostic factor for complications of major head and neck surgery. Arch Otolaryngol Head Neck Surg 2005;131:605-609. 22. Kim BD, Hsu WK, De Oliveira GS, Jr., et al. Operative duration as an independent risk factor for postoperative complications in single-level lumbar fusion: an analysis of 4588 surgical cases. Spine (Phila Pa 1976) 2014;39:510-520. 23. Macario A. What does one minute of operating room time cost? J Clin Anesth 2010;22:233-236.

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Figure 1. Two spinal needles are then inserted using sterile gloves through the skin into the paraspinal muscles

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Figure 2. Cross-table lateral radiograph is then taken with the two needles in place prior to draping

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Figure 3. Image is reviewed and printed for the room, confirming both spinal needles, sacrum, and indicated surgical levels are visible in the image for a L4-5 fusion for spondylolisthesis

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Figure 4. Location of the needles is marked with a line perpendicular to the spine prior to removing the needles and covering the surgical site with Ioban™.

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Figure 5. Example of superficial localization cross-table lateral radiograph in a patient undergoing posterior lumbar fusion with instrumentation of L2-L3, allowing the surgeon to adjust their planned incision for the intended operative levels.

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Figure 6. Example of correct deep localization cross-table lateral radiograph with spinal needles inserted into the L2/L3 and L3/L4 facet capsules in a patient undergoing lumbar decompression of L3-S1, since the L3-4 facet is at the level of the caudal needle

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Figure 7. Example of a unintended-level exposure with spinal needle inserted into the facet capsule of L2/L3 in a patient undergoing lumbar decompression of L4-L5, since the needle does not mark an area that is within the intended surgical field

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Figure 8. Graphical representation of the number of procedures per spinal level included in the case series.

0200400600800

100012001400160018002000

T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 L1 L2 L3 L4 L5 S1

Proc

edur

es

Spinal Level

Number of Procedures per Spinal Level

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Robert Runner, MD PGY-5 Administrative Chief Resident

UPCOMING FELLOWSHIP TRAINING: Adult Reconstruction Fellowship Hoag Institute Orthopaedic Specialty Institute Irvine, CA EDUCATION: Emory University School of Medicine Atlanta, GA Doctor of Medicine, May 2013 University of Virginia, Charlottesville, VA Bachelor of Science, Biology and Economics, May 2009

PUBLICATIONS: Work in Progress – Textbook contracted with Springer, “The Evaluation of the Orthopaedic Trauma Patient” Senior Editor with Aaron Morgenstein, MD. Publication in December 2017. Fifty-chapter textbook outlining the essential evaluation of orthopaedic trauma patients through a case example format Vu CCL, Runner RP, Reisman WM, Schenker ML. The frail fail: Increased mortality and post-operative complications in orthopaedic trauma patients. Injury. 2017 Nov;48(11):2443-2450. doi: 10.1016/j.injury.2017.08.026. Epub 2017 Aug 18. PubMed PMID: 28888718. Bellamy JL, Runner RP, Vu CCL, Schenker ML, Bradbury TL, Roberson JR. Modified Frailty Index Is an Effective Risk Assessment Tool in Primary Total Hip Arthroplasty. J Arthroplasty. 2017 Oct;32(10):2963-2968. doi:10.1016/j.arth.2017.04.056. Epub 2017 May 4. PubMed PMID: 28559198. Runner RP, Bellamy JL, Vu CCL, Erens GA, Schenker ML, Guild GN 3rd. Modified Frailty Index Is an Effective Risk Assessment Tool in Primary Total Knee Arthroplasty. J Arthroplasty. 2017 Sep;32(9S):S177-S182. doi:10.1016/j.arth.2017.03.046. Epub 2017 Mar 29. PubMed PMID: 28442185. Runner R, Whicker E, De S. Delayed Radial Nerve Palsy after Closed Reduction of a Pediatric Humeral Shaft Fracture. Case Rep Orthop. 2017;2017:9723497. doi: 10.1155/2017/9723497. Epub 2017 Dec 28. PubMed PMID: 29445558; PubMed Central PMCID: PMC5763207. Runner RP, Mener A, Bradbury TL. Renal Failure after Articulating Antibiotic Hip Arthroplasty Requiring Explantation. Arthroplasty Today. 2017 Article in Press Runner RP, Ahearn BM, Guild GN 3rd. Unusual presentation of failed metal-on-metal total hip arthroplasty with features of neoplastic process. Arthroplast Today. 2016 Dec 3;3(2):71-76. doi: 10.1016/j.artd.2016.10.004. eCollection 2017 Jun. PubMed PMID: 28695177; PubMed Central PMCID: PMC5485231. Runner RP, Bellamy JL, Roberson JR. Gross Trunnion Failure of Cobalt-Chromium Head on Titanium Stem at Midterm Follow-Up: A Report of 3 Cases. JBJS Case Connector. 2016;6:e96. Doi:10.2106/JBJS.CC.16.00054 Guild GN 3rd, Runner RP, Castilleja GM, Smith MJ, Vu CL. Efficacy of Hybrid Plasma Scalpel in Reducing Blood Loss and Transfusions in Direct Anterior Total Hip Arthroplasty. J Arthroplasty. 2017 Feb;32(2):458-462. doi:10.1016/j.arth.2016.07.038. PubMed PMID: 27659394.

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Schur MD, Andras LM, Broom AM, Barrett KK, Bowman CA, Luther H, Goldstein RY, Fletcher ND, Millis MB, Runner R, Skaggs DL. Continuing Delay in the Diagnosis of Slipped Capital Femoral Epiphysis. J Pediatr. 2016 Jul 25. pii:S0022-3476(16)30395-X. doi: 10.1016/j.jpeds.2016.06.029. [Epub ahead of print] PubMed PMID: 27470686. Guild GN 3rd, Runner RP, Rickels TD, Oldja R, Faizan A. Anthropometric Computed Tomography Reconstruction Identifies Risk Factors for Cortical Perforation in Revision Total Hip Arthroplasty. J Arthroplasty. 2016 Apr 13. pii:S0883-5403(16)30054-7. doi: 10.1016/j.arth.2016.04.006. [Epub ahead of print] PubMed PMID: 27212394. Runner R, Moore T Jr, Reisman W. Value of a Dedicated Saturday Orthopaedic Trauma Operating Room. J Orthop Trauma. 2016 Jan;30(1):e24-9. doi:10.1097/BOT.0000000000000441. PubMed PMID: 26360537. Vladimir R. Babaev, Robert P. Runner, Gökhan S. Hotamisligil, MacRae F. Linton, et al: Macrophage Mal1 Deficiency Suppresses Atherosclerosis in Low-Density Lipoprotein Receptor–Null Mice by Activating Peroxisome Proliferator-Activated Receptor-γ–Regulated Genes. Arteriosclerosis, Thrombosis, and Vascular Biology. 2011 Jun;31(6):1283-90. Epub 2011 Apr 7. PubMed PMID: 21474828. Martin, M. L., Snyder, A. E., Awosogba, T., Blue, K., Brown, D., Davis, S., Runner, R., . Vasireddy, P. (2011). Public Health and Disaster Preparedness in St. Kitts and Nevis. The Journal of Race & Policy, 7(1), 42-52. Retrieved from http://search.proquest.com/docview/1460166057?accountid=10747. RESEARCH EXPERIENCE

Emory University, Department of Orthopaedics The Sick and “Not Cleared”: Is there a Critical Window for Debridement of Open Fractures?; Mara Schenker, MD, Amanda Mener, BA; Christopher Staley, BA; William Reisman, MD

poster presentation OTA 2017, Vancouver, British Columbia, Canada Frailty Predicts Mortality and Complications in Chronologically Young Patients with Traumatic Orthopaedic Injuries; Mara Schenker, MD

Poster presentation OTA 2017, Vancouver, British Columbia, Canada Podium presentation, American Academy of Orthopaedic Surgeons Annual

Meeting, New Orleans, LA, March 2018 Sarcopenia Predicts Frailty and Poor Outcomes in Elderly Lower Extremity Fractures; Mara Schenker, MD; Adam Singer, MD

• Poster presentation OTA 2017, Vancouver, British Columbia, Canada • Podium presentation, American Academy of Orthopaedic Surgeons Annual

Meeting, New Orleans, LA, March 2018 Misdiagnosis and Radial Tunnel Syndrome: Considering the Distal Biceps Tendon; Gary McGillivary, MD

• e-poster presentation; Eastern Orthopaedic Association Annual Meeting, Miami, FL, Oct. 2017

• Accepted for publication in Journal of Surgical Orthopedic Advances Computed Tomography versus Magnetic Resonance Imaging in the Detection of Major Soft Tissue Pathology following Traumatic Knee Dislocation; Mara Schenker, MD; Adam Singer, MD Data in collection

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Venous Thromboembolism Prophylaxis Trends as Reported by American Board of Orthopaedic Surgery Part II Candidates; James R. Roberson, MD; Michael Gottschalk, MD

• Podium presentation, American Academy of Orthopaedic Surgeons Annual Meeting, New Orleans, LA, March 2018

Motorcycles and Helmets: Dangers of Repealing Universal Helmet Laws; Mara L. Schenker, MD; Samir Mehta, MD

• SOA/OREF Resident Award Paper, Podium presentation: Southern Orthopaedics Association annual meeting, Hilton Head, SC, June 2017

Concurrent Surgery: A State-of-the-Union; Mara L. Schenker, MD; Samir Mehta, MD; Michael Gottschalk, MD

• Podium and poster presentation, AOA annual meeting, Charlotte, NC, June 2017

• Counsel of Orthopaedic Residency Directors CORD conference podium presentation, Charlotte, NC 2017

• e-poster presentation, American College of Surgeons 2017 Clinical Congress, San Diego, CA, October 2017

• Poster presentation, American Academy of Orthopaedic Surgeons Annual Meeting, New Orleans, LA, March 2018

• Manuscript submitted to Academic Medicine Clinical Outcomes of Patients with Lateral Femoral Cutaneous Nerve Injury during Direct Anterior Total Hip Arthroplasty; Thomas L. Bradbury, MD; Adam Sunderland, MD.

• Manuscript submitted to JOA • Podium presentation, American Academy of Orthopaedic Surgeons Annual

Meeting, New Orleans, LA, March 2018 Renal Failure after Articulating Antibiotic Hip Arthroplasty Requiring Explantation; Tom Bradbury, MD, Amanda Mener, BA

• Article published in Arthroplasty Today: http://www.arthroplastytoday.org/article/S2352-3441(17)30022-5/fulltext

Trends in Post-Operative Infections in Following Primary Joint Arthroplasty and Spinal Fusion: A 7-year Review; Greg Erens, MD, Keith Michael, MD; Scott Boden, MD, Thomas Bradbury, MD; James Roberson, MD; George Guild, MD

• Manuscript in preparation, • Rapid fire presentation: Southern Orthopaedics Association annual

meeting, Hilton Head, SC, June 2017 • Podium Presentation, OREF/ORS Southeast Region Resident Research

Symposium, Atlanta, GA, February 2018 • Poster presentation, Musculoskeletal Research Symposium, Emory

University, Atlanta, GA, February 2018

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• Poster presentation, American Academy of Orthopaedic Surgeons Annual Meeting, New Orleans, LA, March 2018

Modified Frailty Index is an Effective Risk Assessment Tool in Primary Total Knee Arthroplasty; George N. Guild III, MD, Jaime Bellamy, DO, Mara L. Schenker, MD, Greg Erens, MD

• Podium presentation; American Association of Hip and Knee Surgeons annual meeting, Dallas, TX, November 2016

• Rapid fire presentation: Society of Military Orthopaedic Surgeons annual meeting, Olympic Valley, CA, December 2016

• Podium presentation: American Academy of Orthopaedic Surgeons annual meeting, San Diego, CA, March 2017

• Poster presentation, AOA annual meeting, Charlotte, NC, June 2017 • Published in Journal of Arthroplasty. PubMed PMID: 28442185

Modified Frailty Index is an Effective Risk Assessment Tool in Primary Total Hip Arthroplasty; James R. Roberson, MD, Jaime Bellamy, DO, Mara Schenker, MD, Thomas L. Bradbury, MD

• Poster presentation, American Association of Hip and Knee Surgeons annual meeting, Dallas, TX, November 2016

• Podium presentation, Society of Military Orthopaedic Surgeons annual meeting, Olympic Valley, CA, December 2016

• Poster presentation, AOA annual meeting, Charlotte, NC, June 2017 • Published in Journal of Arthroplasty. PubMed PMID: 28559198

Delayed Radial Nerve Palsy after Closed Reduction of Pediatric Humeral Shaft Facture: A Case Report; Sayan De, MD

• Published in Case Reports Orthopedics. PubMed PMID: 29445558

Power versus Hand Screwdriver for Lag Screw Insertion; Thomas J. Moore, Jr, MD

• Collected data from 48 participants, Manuscript in preparation, abstract submitted to Southern Orthopaedics Association annual meeting 2017

• Poster presentation, William E. Booth and James Zaidan Resident Research Day at Grady Memorial Hospital, Atlanta, GA, May, 2017

Unusual Presentation of Failed Metal on Metal Total Hip Arthroplasty with Features of Neoplastic Process; George N. Guild III, MD, Briggs Ahearn, MD

• Published Arthroplasty Today (2016), http://dx.doi.org/10.1016/j.artd.2016.10.004

Femoral versus Adductor Canal Nerve Block in Anterior Cruciate Ligament Reconstruction: A Prospective, Double-Blinded, Randomized Trail; John Xerogeanes, MD

• Manuscript Submitted to American Journal of Sports Medicine • Rapid fire presentation: Southern Orthopaedics Association annual

meeting, Hilton Head, SC, June 2017 • Richmond Arthroscopy/Sports Medicine Resident Award Paper and Podium

Presentation; Eastern Orthopaedic Association annual meeting, Miami, FL, October 2017

44

Anthropometric Computed Tomography Reconstruction Identifies Risk Factors for Cortical Perforation in Revision Total Hip Arthroplasty; George N. Guild III, MD

• Published in Journal of Arthroplasty. PubMed PMID: 27212394. Posterior Labral Repairs in Baseball Players; Xavier Duralde, MD, James Kercher, MD, Tim McCarthy, MD

• Podium presentation, Society of Military Orthopaedic Surgeons annual meeting, Scottsdale, AZ, December 2017

• Podium presentation, American Academy of Orthopaedic Surgeons Annual Meeting, New Orleans, LA, March 2018

Efficacy of Hybrid Plasma Scalpel in Reduced Blood Loss and Transfusions in Direct Anterior Total Hip Arthroplasty; George N. Guild III, MD, Cathy Vu, BA

• Podium Presentation; Eastern Orthopaedic Association annual meeting; New Orleans, LA, October 2016

• Published in Journal of Arthroplasty 2017. PubMed PMID: 27659394. Follow Up Care for Patients with Ballistic Long Bone Lower Extremity Fractures at a Level 1 Trauma Center: A Retrospective Review; Thomas J. Moore, Jr, MD, Rafael Arceo, BA, Michael Gottschalk, MD

• Abstract accepted to AOA Annual meeting 2017 • Manuscript in preparation • Rapid fire presentation: Southern Orthopaedics Association annual meeting,

Hilton Head, SC, June 2017 • Poster Presentation; Southeastern Medical Scientist Symposium annual

meeting, Birmingham, AL, November 2016 The Frail Fail: Increased Post-Operative Complications and Mortality and Orthopaedic Trauma Patients; Mara Schenker, MD, Cathy Vu, BA, William Reisman, MD

• Poster presentation, AOA annual meeting, Charlotte, NC, June 2017 • Podium presentation: American Academy of Orthopaedic Surgeons annual

meeting, San Diego, CA, March 2017 • Southern Orthopaedics Association annual meeting, Hilton Head, SC, June 2017 • Podium Presentation; 1st place M. Gage Ochsner Resident Research Paper 2016,

Georgia Society of American College of Surgeons annual meeting, Savannah, GA. Will present at regional meeting in Kentucky, November 2016

• Rapid fire presentation; Eastern Orthopaedic Association annual meeting; New Orleans, LA, October 2016

• Published in Injury: PubMed PMID: 28888718. Gross Trunnion Failure of Cobalt-Chromium Head on Titanium Stem at Midterm Follow-Up: A Report of 3 Cases; James R. Roberson, MD, Jaime Bellamy, DO

• Published in JBJS Case Connector: http://journals.lww.com/jbjscc/Abstract/2016/ 06040/Gross_Trunnion_Failure_of_a_Cobalt_Chromium.17.aspx

45

Continuing Delay in the Diagnosis of Slipped Capital Femoral Epiphysis; Nicholas Fletcher, MD, Lindsay Andras, MD, David Skaggs, MD, et. al.; Children’s Hospital Los Angeles, Children’s Healthcare of Atlanta, Children’s Hospital Boston

• Podium presentation; Southern Orthopaedics Association annual meeting, Asheville, NC, July 2015

• Podium presentation by co-author at American Academy of Pediatrics annual meeting; Washington, DC, October 2015

• Podium Presentation by co-author; American Academy of Orthopaedic Surgeons annual meeting, Orlando, FL, March 2016

• Podium Presentation; 3rd place resident research award; Kelly Day Research Symposium; Atlanta, GA, June 2016

• Published in Journal of Pediatrics; PubMed PMID: 27470686. The Value of a Saturday Dedicated Orthopaedic Trauma Room; William M. Reisman, MD, Thomas J. Moore Jr., MD

• 1st place poster presentation; Atlanta Trauma Symposium, Atlanta, GA; April 2013

• Podium presentation; 2nd place M. Gage Ochsner Resident Paper Competition; Georgia Society of the American College of Surgeons annual meeting, Macon, GA; August 2013

• Podium presentation; 3rd place Thomas Whitesides Resident Research Award; Georgia Orthopaedics Society annual meeting, Sea Island, GA; September 2014

• Podium presentation; Kelly Day Research Symposium; Atlanta, GA June 2014 • Podium presentation; Southern Orthopaedics Association annual meeting,

Beaver Creek, CO; July 2014 • Poster presentation, Emory Quality Conference, Atlanta, GA; June 2016 • Poster presentation, Booth Zaidan Resident Research Day, Atlanta, GA, June

2016 • Published in Journal of Orthopaedic Trauma; PubMed PMID: 26360537.

Ossification of the Posterior Longitudinal Ligament Causing Severe Progressive Cervical Myelopathy: A Case Presentation; John G. Heller, MD

46

Utilization Patterns, Efficacy, and Complications of Venous Thromboembolism Prophylaxis Regimens in Primary Hip and Knee Arthroplasty as Reported by American Board of Orthopaedic Surgery Part II Candidates Robert P. Runner, MD, Michael B. Gottschalk, MD, Poonam P. Dalwadi, BS, Aidin E. Pour, MD, James R. Roberson, MD Background: Many strategies for venous thromboembolism (VTE) prophylaxis following hip and knee arthroplasty exist, with extensive controversy regarding the optimum strategy to minimize risk of VTE and bleeding complications. Data from the American Board of Orthopaedic Surgery (ABOS) Part II (oral) Examination case list database was analyzed to determine efficacy, complication rates and prescribing patterns for different prophylactic regimens. Methods: The ABOS case database was queried utilizing Current Procedural Terminology (CPT) codes 27447 and 27130 for primary total knee and hip arthroplasty, respectively. Geographic region, patient age, gender, DVT prophylaxis regimen and complications were obtained. Minimal prophylaxis patterns were considered if only sequential compression devises (SCDs), aspirin or no prophylaxis strategy was utilized. Aggressive VTE prophylaxis patterns were considered if any of low molecular weight heparin (enoxaparin), warfarin, rivaroxaban, fondaparinux or other strategies were used. Results: 14,089 cases of primary joint arthroplasty were identified from 2014-2015. Average age was 64.5 years; 57.7% were female. The national rate of minimal VTE prophylaxis regimens was 37.2% while aggressive regimens were used in 62.8% of patients. Significant regional differences in prophylactic regimen patterns exist between the 6 regions. Use of minimal intensity prophylaxis strategy was significantly associated with patients having no complications (94.7% vs 91.8%). Use of aggressive prophylaxis patterns was associated with higher likelihood of a moderate thrombotic event (1.98% vs 0.62%), moderate bleeding event (4.48% vs 3.17%), severe bleeding event (1.80% vs 1.41%) and death within 90 days (0.65% vs 0.36%). There was no significant difference in the rate of fatal pulmonary embolism between minimal or aggressive prophylactic regimens. Conclusions: It was not possible to ascertain the individual rationale for use of more aggressive VTE prophylaxis regimens; however, more aggressive regimens were associated with higher rates of bleeding and thrombotic complications. Less aggressive regimens were not associated with a higher rate of thrombosis. This analysis indicates that a less aggressive VTE prophylaxis regimen is safe and effective in appropriate patients when compared to more aggressive regimens. Level of Evidence: Therapeutic Level III. Disclaimer: All views expressed in the study are the sole views of the authors and do not represent the views of the American Board of Orthopaedic Surgery.

47

INTRODUCTION Joint arthroplasty is expected to exponentially increase in the coming years with up to 527,000 annual

primary total hip arthroplasty (THA) and 3.48 million annual primary total knee arthroplasty (TKA) procedures

by 2030.1 A major controversial issues with arthroplasty care is how best to manage post-operative venous

thromboembolism (VTE) prophylaxis. Multiple regimens exist and the selection is often made subjectively

based on or local or regional practice patterns and medicolegal environment.

It is important to note that there is a spectrum of VTE among patients. Non-clinically significant deep

vein thrombosis (DVT) rates can be as high as 12.6% - 31.1% following primary arthroplasty.2, 3 Clinically

significant DVT rates are significantly lower at 0.75% - 2.1%.4-6 The more significant VTE complication of a

pulmonary embolism (PE) ranges from 0.41% to 1.93%.4, 7-10 However, even when matched cohort of patients

with non-fatal VTE were compared to those who did not have a VTE after TKA, there were no differences in

patient reported clinical outcomes at 2 years.11

Several studies have evaluated the catastrophic complication of fatal pulmonary embolism and found

it to be extremely rare following primary joint arthroplasty: 0.07%,12 0.10%,4 0.01%,7 0.024%,5 0.02%,9

0.034%.10 Death from any cause in the early postoperative period following primary joint arthroplasty is slightly

higher ranging between 0.31%7, 12 and 0.51%.8 Anticoagulants used to prevent these thrombotic complications

have inherent risks themselves with major bleeding events ranging from 0.12% - 2.3%.3, 5 The optimum strategy

minimizes the risk of VTE while not placing the patient at increased risk for bleeding complications associated

with anticoagulation. Cost is also a significant factor.

To evaluate trends in VTE prophylaxis prescribing patterns, data from the American Board of

Orthopaedic Surgery (ABOS) Part II (oral) examination case list database was analyzed to determine frequency

of utilization, regional practice patterns, effectiveness of thrombosis prevention and bleeding complications of

different prophylactic regimens.

The null hypothesis is that there are no differences in bleeding or thrombotic events based on the type

of VTE prophylaxis used. Additionally, we hypothesize that there are no regional differences in VTE prophylaxis

prescribing patterns amongst the 6 national regions.

Materials and Methods:

Institutional review board approval was not required as this was deidentified data from a database.

The ABOS provided data from its proprietary database (Scribe). The ABOS case list database is a collection of

surgical cases that are self-reported by orthopaedic candidates approved for admission to the ABOS Part II

examination. Orthopaedic candidates must have completed an accredited orthopaedic residency, passed the

ABOS Part I examination, actively practiced orthopaedic surgery for at least 20 months in the same location,

and undergone peer review.13 Candidates report their cases during a 6-month period (April through September)

prior to their application for certification. As candidates must certify their case log (with notarized confirmation

48

by their hospital medical records department) by the end of October, a maximum of a 7-month follow-up

(range, 1 to 7 months) is available in the database. Each surgical case was de-identified for research purposes.

The data set is verified via sampling during the examination, as any of the cases input into the Scribe database

may be chosen for review.14

The Scribe data entry system was modified to begin collecting VTE prophylaxis regimens, bleeding and

thrombotic complications beginning in 2014. The data from 2014 and 2015 was queried for Current Procedural

Terminology (CPT) codes 27447 and 27130 for primary total knee and hip arthroplasty, respectively.

Geographic region (Midwest, Northeast, Northwest, South, Southeast, Southwest), year of surgery, diagnosis

code, age, sex of the patient and surgeon-reported complications were analyzed. Complications are reported

on a per-case basis with no limit for the number of complications for each case. The patients were separated

into two groups based on VTE prophylaxis strategy (Table 1). Minimal prophylaxis patterns were considered if

only sequential compression devises (SCDs), aspirin or no prophylaxis strategy was utilized. Aggressive VTE

prophylaxis patterns were considered if any of low molecular weight heparin (enoxaparin), warfarin,

rivaroxaban, fondaparinux or other strategies were used. Complications were grouped into none, moderate

thrombotic, moderate hemorrhagic, severe thrombotic, severe hemorrhagic and catastrophic (Table 1). A

patient was considered to have no complications if no venous thromboembolism occurred and there was

uneventful wound healing. Moderate thrombotic complications included: non-fatal PE, DVT proximal to the

knee, DVT distal to the knee, and superficial venous thrombosis. Moderate hemorrhagic events included:

wound infection not requiring surgery, hematoma not requiring surgery, upper or lower gastrointestinal (GI)

bleed, retroperitoneal hematoma, hematuria, or other bleeding event. Severe thrombotic event was a fatal

PE. Severe hemorrhagic events were: deep infection requiring return to the operating room (OR), hematoma

requiring return to the OR, or hemorrhagic stroke. The catastrophic event of death within 90 days was also

analyzed.

Statistical analysis was performed using JMP Pro Software (version 10; SAS Institute). A p value of <0.05

was considered significant. Comparisons of categorical variables between the 2 cohorts used the chi-square

test if the sample size was ‡10 or the Fisher exact test if the sample size was <10. Comparisons of continuous

variables with a normal distribution used the Student t test. To control for certain variables, a multivariate

logistic regression was performed and odds ratios (ORs) were calculated. As this study utilized a proprietary

database, a sample size of convenience was used.

Source of funding: There were no sources of funding for this study.

49

Results:

14,089 cases of primary joint arthroplasty were identified from 2014 - 2015. The average age was 64.5

years; 57.7% were female. Table 2 illustrates the caseload distribution of TKA and THA by gender. 7,236

(51.4%) primary arthroplasty procedures were performed in 2014, the remaining 6,853 (48.6%) in 2015. 7,467

cases (53.0%) were primary TKA, 6,622 (47.0%) were primary THA. The overall national rate of minimal VTE

prophylaxis regimens in primary arthroplasty patients was 37.2% while aggressive regimens were used in 62.8%

of patients. In the minimal intensity group, there were only 9 patients (0.064%) who received no VTE

prophylaxis postoperatively; the remainder had aspirin, SCDs, or both. Significant regional differences in

prophylactic regimen patterns existed between the 6 regions (p<0.0001).

Table 3 illustrates the significant differences in complications for all arthroplasty patients receiving

aggressive vs minimal prophylaxis strategies. The use of minimal intensity prophylaxis strategy was associated

with patients having no complications (94.7% vs 91.8%, p<0.0001). Use of aggressive prophylaxis patterns was

associated with higher likelihood of a moderate thrombotic event (1.98% vs 0.62%, p<0.0001), moderate

bleeding event (4.48% vs 3.17%, p<0.0001), severe bleeding event (1.80% vs 1.41%, p=0.0404) and death within

90 days (p=0.0122). Fatal PE occurred in 4 (0.046%) patients treated with aggressive VTE prophylaxis and no

patients with minimal VTE prophylaxis. The overall rate of fatal PE was 0.028%. There was no significant

difference in the rate of fatal pulmonary embolism between minimal or aggressive prophylactic regimens

(p=0.1490). 19 patients (0.36%) in the minimal prophylaxis and 57 patients (0.65%) in the aggressive

prophylaxis group died within 90 days of surgery. The overall rate of death within 90 days for the cohort was

0.54%.

A subgroup analysis was performed on patients undergoing TKA (Table 4). In patients undergoing TKA,

the use of minimal intensity prophylaxis strategy was significantly associated with patients having no

complications (94.9% vs 91.1%, p<0.0001). Use of aggressive prophylaxis patterns in TKA was associated with

higher likelihood of a moderate thrombotic event (2.42% vs 0.42%, p<0.0001), moderate bleeding event (4.99%

vs 3.52%, p=0.0018), severe bleeding event (1.74% vs 1.21%, p=0.0462) and death within 90 days (0.60% vs

0.19%, p=0.0068). Fatal PE occurred in 4 (0.08%) patients treated with aggressive VTE prophylaxis and no

patients with minimal VTE prophylaxis (p=0.1747).

Similar subgroup analysis of patient undergoing THA (Table 5) revealed that use of minimal intensity

prophylaxis strategy was significantly associated with patients having no complications (94.4% vs 92.6%,

p=0.0015). Use of aggressive prophylaxis patterns was associated with higher likelihood of a moderate

thrombotic event (1.43% vs 0.82%, p=0.0146), moderate bleeding event (3.85% vs 2.82%, p=0.0137). Severe

bleeding events and catastrophic death within 90 days were not significantly associated with specific

prophylaxis patterns in THA. No fatal pulmonary embolisms occurred in patients undergoing THA thus

statistical comparison between the groups was unable to be performed.

50

The distribution of caseload among the regions is outlined in Figure 1. The Southwest (1760), Midwest

(1609) and Northeast (1476) had the highest volumes of TKA while the Northeast (1452), Midwest (1350) and

Southwest (1256) had the highest volumes of THA. The breakdown of prophylaxis strategies by region is

illustrated in Figure 2. Only the Southeast region had a higher proportion (68.5%) for aggressive VTE

prophylaxis strategies than the national average (62.8%). All other regions used a lower frequency of

aggressive prophylactic strategies: Northwest (55.8%); Southwest (59.7%); South (61.7%); Northeast (62.0%);

Midwest (62.8%). Thus, all regions except the Southeast, use minimal intensity VTE prophylaxis strategies more

frequently than the national average, and these differences were significant (p<0.0001).

Discussion:

The perfect VTE prophylaxis strategy would prevent all thromboembolic events and cause no harm to

patients; however, this perfect regimen does not exist. A review of 21 studies from 1995-2015 of 34,764

patients using a variety of prophylaxis strategies calls into question the notion of pulmonary embolus as a

“never event” and suggests that even healthy patients receiving aggressive anticoagulation regimens are still

at risk for VTE and that some thrombotic events may never be avoided.15 Thus, providers seek to determine

optimum regimens that are safe, effective with minimal harm to the patient and reduce the risk of clinically

significant VTE. Over the past decades there have been several iterations of appropriate guidelines between

the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP)

with a push for appropriately powered randomized controlled trials to compare regimens.16 Recent systematic

review and meta-analysis showed significant heterogeneity in dosing regimens among the prior literature17

which agrees with our results showing significant differences in prescribing patterns across the nation.

One argument for these differences in post-operative VTE prophylaxis patterns relates to the diversity

of patients treated with arthroplasty and the need for individualized risk stratification. Parvizi et. al. identified

several patient factors that independently increase pulmonary embolism risk including: obesity, surgeries on

the knee, elevated Charlson Comorbidity index, chronic obstructive pulmonary disease, atrial fibrillation,

anemia, depression, and post-operative DVT.9 However, it is not clear that more aggressive VTE prophylaxis

regimens decrease the likelihood of a thrombotic event in these patients.

To try to mitigate risk and cost, institutions transitioned to risk stratification protocols for low risk and

high risk patients and showed success18 with some showing reduction of 70-75% of aggressive strategies while

maintaining low incidences of symptomatic VTE.19, 20 But do we need to treat these supposed “higher risk”

patients any differently? Even when the “higher” risk patients were isolated and compared for the use of

aspirin and warfarin, the incidence of VTE, prosthetic joint infection, and mortality were higher for those who

received warfarin, showing that aspirin was safer.21 These findings agree with our results showing that

51

aggressive VTE prophylaxis strategies are associated with increased risk for moderate thrombotic, moderate

bleeding, severe bleeding, and catastrophic events. While minimal strategies were associated with fewer

complications. In our sample, there were only 9 patients (0.064%) who received no VTE prophylaxis

postoperatively. Thus, the superior results for the minimal prophylaxis strategies are essentially for aspirin,

SCDs or both. We cannot conclude that no DVT prophylaxis is appropriate in arthroplasty patients; though, the

use of aspirin, SCDs or a combination of the two has improved results compared to the more aggressive

strategies in our sample.

More aggressive prophylaxis strategies come with their own set of risks. When warfarin is compared

to aspirin for VTE prophylaxis following arthroplasty, the more aggressive strategy of warfarin was associated

with higher rates of prosthetic joint infection (1.5% vs 0.4%).22 Comparison of aspirin and warfarin shows a

lower direct cost of index hospitalization and total episode of care charges for patients who received aspirin

for VTE prophylaxis.23 Markov theoretical modeling analysis comparing low-molecular-weight heparin to

aspirin also shows that aspirin is more cost-effective.24

More recent literature indicates that even low dose aspirin regimens are superior to high dose. In a

study of 4,651 primary joint arthroplasty from 2013-2015, low dose aspirin of 81mg twice daily was shown to

be not inferior to the 325mg twice daily dosing with respect to incidence of VTE, prosthetic joint infection and

90-day mortality.25 The use of higher dose aspirin is associated with more gastrointestinal side effects than

lower 81mg dose. 26

A study from Singapore in 2012 showed that out of 531 patients undergoing primary TKA, only 0.75%

had a clinically significant VTE.6 Similar to the Asian study, in a larger sample of 4037 patients, patients were

risk-stratified pre-operatively where only high risk patients received chemoprophylaxis and the rest received

mechanical prophylaxis alone. Only 1 patient (.024%) had a fatal pulmonary embolism and there were only 5

(0.124%) bleeding events.5 Even in low energy fracture patients the incidence of clinically significant VTE is low

at 1.4% with 0.012% having a fatal PE.27 Thus, proper risk stratification of patients can lead to appropriate and

more frequent use of minimal VTE prophylaxis strategies. Cusick and Beverland even go as far as to say the

elective hip and knee replacement should no longer be considered high-risk procedures for VTE.12

As detailed in Figure 2, there are significant regional variations in VTE prophylaxis strategies across the

nation. The national trend was that nearly two-thirds of providers prescribe more aggressive VTE prophylaxis

regimens of enoxaparin, warfarin, rivaroxaban, fondaparinux or other strategies. The Southeast has

significantly more aggressive VTE prophylaxis prescribing patterns at 68.5% comparted to the national average

of 62.8%. The Northwest and Southwest were the fewest prescribers of aggressive VTE prophylaxis regimens

at 55.8% and 59.7%, respectively. Whether these differences are from inherent differences in the patient

populations treated or variations in the medicolegal atmosphere in these geographic regions is unknown

52

Strengths and Weaknesses of the Study

Strengths:

One of the major strengths of this study is the large cohort of patients (14,089) and the power to detect

differences in rare events between the groups. Additionally, the quality of data and accuracy of reporting for

VTE and bleeding complications is high as each case had the potential to be selected for full review during the

Part II (oral) examination.

Another strength was the ability to report recent observed incidences of patient complications. This up

to date reporting will aid providers in counseling patients for informed consent. The overall death rate within

the follow-up case collection period for patients having primary hip or knee arthroplasty was 0.54%. The overall

rate of fatal pulmonary embolism was 0.028%. No fatal PE occurred in the THA cohort within the 1-7 month

follow-up period.

Limitations:

One limitation of this database in addition to inherent limitations of self-reported data is that individual

patient comorbidities are not captured. Thus, risk stratification for patients for higher risk VTE cannot be

calculated and causation cannot be proven. It is likely that perceived higher risk patients received more

aggressive VTE prophylaxis regimens as the specific regimen prescribed was up to surgeon discretion. Surgeon

clinical judgment and regional preferences are likely strong influences on prescribing patterns. In a

retrospective review of 26,391 primary and revision arthroplasty cases from 2000-2011, Parvezi et. al.

identified several independent risk factors for symptomatic pulmonary embolism.9 Further variables that have

been associated with higher incidences of PE are age, American Society of Anesthesiologist score of 3 or higher

and the use of general anesthesia.7 Other data showed through regression models that there was no

association between the type of VTE prophylaxis or type of anesthesia for increased odd of pulmonary

embolism when adjusting for age, sex, and ASA score.8

One of the inherent issues with the ABOS Part II operative database is that the follow up ranges from

1 month to 7 months maximum. Although we are unable to collect 2-year outcome data for all patients, the

nature of these bleeding and thrombotic complications are likely to occur within the immediate post-operative

period and would be captured by the 1-7 month follow-ups for this group. Additionally, the surgeons

performing these arthroplasty cases are typically early in practice and decisions are likely strongly influenced

by residency and fellowship training patterns rather than their own experience. The database is also unable to

distinguish from arthroplasty cases performed by arthroplasty fellowship trained candidates, generalists or

other subspecialty fellowship candidates.

53

Conclusions and Implications of the Study

Although we were not able to ascertain the individualized medical rationale for the use of aggressive

VTE prophylactic regimens, more aggressive regimens were associated with higher rates of bleeding and

thrombotic complications. Less aggressive regimens were not associated with a higher rate of thrombosis.

This analysis indicates that a less aggressive VTE prophylaxis regimen is safe and effective in appropriate

patients when compared to more aggressive regimens.

References

1. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007 Apr;89(4):780-5. 2. Freedman KB, Brookenthal KR, Fitzgerald RH, Jr., Williams S, Lonner JH. A meta-analysis of thromboembolic prophylaxis following elective total hip arthroplasty. J Bone Joint Surg Am. 2000 Jul;82-A(7):929-38. 3. Migita K, Bito S, Nakamura M, Miyata S, Saito M, Kakizaki H, et al. Venous thromboembolism after total joint arthroplasty: results from a Japanese multicenter cohort study. Arthritis Res Ther. 2014 Jul 21;16(4):R154. 4. Sarmiento A, Goswami A. Thromboembolic disease prophylaxis in total hip arthroplasty. Clin Orthop Relat Res. 2005 Jul(436):138-43. 5. Hamilton WG, Reeves JD, Fricka KB, Goyal N, Engh GA, Parks NL. Mechanical thromboembolic prophylaxis with risk stratification in total knee arthroplasty. J Arthroplasty. 2015 Jan;30(1):43-5. 6. Bin Abd Razak HR, Soon AT, Dhanaraj ID, Tan AH. Incidence of clinically significant venous thromboembolic events in Asian patients undergoing total knee arthroplasty without anticoagulation. J Arthroplasty. 2012 Jun;27(6):1128-32. 7. Khatod M, Inacio MC, Bini SA, Paxton EW. Pulmonary embolism prophylaxis in more than 30,000 total knee arthroplasty patients: is there a best choice? J Arthroplasty. 2012 Feb;27(2):167-72. 8. Khatod M, Inacio MC, Bini SA, Paxton EW. Prophylaxis against pulmonary embolism in patients undergoing total hip arthroplasty. J Bone Joint Surg Am. 2011 Oct 05;93(19):1767-72. 9. Parvizi J, Huang R, Raphael IJ, Arnold WV, Rothman RH. Symptomatic pulmonary embolus after joint arthroplasty: stratification of risk factors. Clin Orthop Relat Res. 2014 Mar;472(3):903-12. 10. Allen C, Seinge R, Maxwell R, Thind D. CT pulmonary angiography and pulmonary embolism following 5809 primary joint arthroplasties. N Z Med J. 2015 May 01;128(1413):41-9. 11. Ast MP, Gorab AH, Banka TR, Lee L, Lyman S, Westrich GH. Clinical outcomes of patients with non-fatal VTE after total knee arthroplasty. J Arthroplasty. 2014 Jan;29(1):37-9. 12. Cusick LA, Beverland DE. The incidence of fatal pulmonary embolism after primary hip and knee replacement in a consecutive series of 4253 patients. J Bone Joint Surg Br. 2009 May;91(5):645-8. 13. Weber SC, Martin DF, Seiler JG, 3rd, Harrast JJ. Superior labrum anterior and posterior lesions of the shoulder: incidence rates, complications, and outcomes as reported by American Board of Orthopedic Surgery. Part II candidates. Am J Sports Med. 2012 Jul;40(7):1538-43. 14. Gottschalk MB, Carpenter W, Hiza E, Reisman W, Roberson J. Humeral Shaft Fracture Fixation: Incidence Rates and Complications as Reported by American Board of Orthopaedic Surgery Part II Candidates. J Bone Joint Surg Am. 2016 Sep 07;98(17):e71. 15. Lieberman JR, Cheng V, Cote MP. Pulmonary Embolism Rates Following Total Hip Arthroplasty With Prophylactic Anticoagulation: Some Pulmonary Emboli Cannot Be Avoided. J Arthroplasty. 2017 Mar;32(3):980-6.

54

16. Lieberman JR, Pensak MJ. Prevention of venous thromboembolic disease after total hip and knee arthroplasty. J Bone Joint Surg Am. 2013 Oct 02;95(19):1801-11. 17. An VV, Phan K, Levy YD, Bruce WJ. Aspirin as Thromboprophylaxis in Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis. J Arthroplasty. 2016 Nov;31(11):2608-16. 18. Odeh K, Doran J, Yu S, Bolz N, Bosco J, Iorio R. Risk-Stratified Venous Thromboembolism Prophylaxis After Total Joint Arthroplasty: Aspirin and Sequential Pneumatic Compression Devices vs Aggressive Chemoprophylaxis. J Arthroplasty. 2016 Sep;31(9 Suppl):78-82. 19. Nam D, Nunley RM, Johnson SR, Keeney JA, Clohisy JC, Barrack RL. The Effectiveness of a Risk Stratification Protocol for Thromboembolism Prophylaxis After Hip and Knee Arthroplasty. J Arthroplasty. 2016 Jun;31(6):1299-306. 20. Nam D, Nunley RM, Johnson SR, Keeney JA, Clohisy JC, Barrack RL. Thromboembolism Prophylaxis in Hip Arthroplasty: Routine and High Risk Patients. J Arthroplasty. 2015 Dec;30(12):2299-303. 21. Huang RC, Parvizi J, Hozack WJ, Chen AF, Austin MS. Aspirin Is as Effective as and Safer Than Warfarin for Patients at Higher Risk of Venous Thromboembolism Undergoing Total Joint Arthroplasty. J Arthroplasty. 2016 Sep;31(9 Suppl):83-6. 22. Huang R, Buckley PS, Scott B, Parvizi J, Purtill JJ. Administration of Aspirin as a Prophylaxis Agent Against Venous Thromboembolism Results in Lower Incidence of Periprosthetic Joint Infection. J Arthroplasty. 2015 Sep;30(9 Suppl):39-41. 23. Gutowski CJ, Zmistowski BM, Lonner JH, Purtill JJ, Parvizi J. Direct Costs of Aspirin versus Warfarin for Venous Thromboembolism Prophylaxis after Total Knee or Hip Arthroplasty. J Arthroplasty. 2015 Sep;30(9 Suppl):36-8. 24. Schousboe JT, Brown GA. Cost-effectiveness of low-molecular-weight heparin compared with aspirin for prophylaxis against venous thromboembolism after total joint arthroplasty. J Bone Joint Surg Am. 2013 Jul 17;95(14):1256-64. 25. Parvizi J, Huang R, Restrepo C, Chen AF, Austin MS, Hozack WJ, et al. Low-Dose Aspirin Is Effective Chemoprophylaxis Against Clinically Important Venous Thromboembolism Following Total Joint Arthroplasty: A Preliminary Analysis. J Bone Joint Surg Am. 2017 Jan 18;99(2):91-8. 26. Feldstein MJ, Low SL, Chen AF, Woodward LA, Hozack WJ. A Comparison of Two Dosing Regimens of ASA Following Total Hip and Knee Arthroplasties. J Arthroplasty. 2017 Jan 24. 27. Prensky C, Urruela A, Guss MS, Karia R, Lenzo TJ, Egol KA. Symptomatic venous thrombo-embolism in low-energy isolated fractures in hospitalised patients. Injury. 2013 Aug;44(8):1135-9.

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TABLE 1. Definitions

Prophylaxis Strategy Interventions

Minimal No Prophylaxis

Sequential Compression Devices (SCDs) Aspirin

Aggressive

Heparin/Enoxaparin Warfarin

Rivaroxaban Fondaparinux

All other prophylactic strategies

Complication Groupings Possible Complications

No complications No venous thromboembolism Uneventful wound healing

Moderate Thrombotic

Non-fatal PE DVT Proximal to Knee

DVT Distal to Knee Superficial VTE

Moderate Bleeding

Wound Infection Not Requiring Surgery Hematoma Not Requiring Surgery

Upper or Lower GI Bleeding Retroperitoneal Hematoma

Hematuria Other (soft tissue hematoma, hemarthrosis in other joints)

Severe Thrombotic Fatal PE

Severe Bleeding Deep Infection Requiring Return to OR

Hematoma Requiring Return to OR Hemorrhagic Stroke

Catastrophic Death Within 90 Days

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TABLE 2. Demographic Data

Age (years)

Gender p-value Male Female

THA 63.7 ± 11.9 3,047 (46.0%) 3,575 (54.0%) 0.5632 TKA 65.3 ± 9.9 2,919 (39.1%) 4,548 (60.9%) 0.0572

TABLE 3. Total Joint Complications Based on Prophylaxis Strategy

Complication Event Prophylaxis Strategy p-value Minimal Aggressive

None 5,050 (94.7%) 8,032 (91.8%) < 0.0001 Moderate Thrombotic 33 (0.62%) 173 (1.98%) < 0.0001

Severe Thrombotic 0 (0%) 4 (0.05%) 0.1490 Moderate Bleeding 169 (3.17%) 392 (4.48%) < 0.0001

Severe Bleeding 75 (1.41%) 158 (1.80%) 0.0404 Catastrophic 19 (0.36%) 57 (0.65%) 0.0122

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TABLE 4. TKA Complications Based on Prophylaxis Strategy

Complication Event Prophylaxis Strategy p-value Minimal Aggressive None 2,503 (94.9%) 4,396 (91.1%) <0.0001

Moderate Thrombotic 11 (0.42%) 117 (2.42%) < 0.0001 Severe Thrombotic 0 (0%) 4 (0.08%) 0.1747 Moderate Bleeding 93 (3.52%) 241 (4.99%) 0.0018

Severe Bleeding 32 (1.21%) 84 (1.74%) 0.0462 Catastrophic 5 (0.19%) 29 (0.60%) 0.0068

TABLE 5. THA Complications Based on Prophylaxis Strategy

Complication Event Prophylaxis Strategy p-value Minimal Aggressive None 2,547 (94.4%) 3,636 (92.6%) 0.0015

Moderate Thrombotic 22 (0.82%) 56 (1.43%) 0.0146 Severe Thrombotic 0 (0%) 0 (0%) - Moderate Bleeding 76 (2.82%) 151 (3.85%) 0.0137

Severe Bleeding 43 (1.59%) 74 (1.88%) 0.2170 Catastrophic 14 (0.52%) 28 (0.71%) 0.2075

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FIGURE 1. Geographic Variation of Surgical Cases

FIGURE 2. Geographic Variation of Prophylaxis Strategy

9471081

1256

1452

533

1350

1009 1034

1760

1476

575

1609

0

200

400

600

800

1000

1200

1400

1600

1800

2000

South Southeast Southwest Northeast Northwest Midwest

Tota

l Cas

es

Region

THA

TKA

38%

31%

40% 38%44%

37%

62%69%

60% 62%56%

63%

0%

10%

20%

30%

40%

50%

60%

70%

80%

South Southeast Southwest Northeast Northwest Midwest

Prop

hyla

xsis

Str

ateg

y Pe

rcen

t

Region

Minimal

Aggressive

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Figure Legends Table 1. Definitions of post-operative VTE prophylaxis for the minimal and aggressive prophylaxis strategies. Groupings of complications considered moderate and severe for bleeding and thrombotic complications. PE = pulmonary embolism. DVT = deep vein thrombosis. VTE = venous thromboembolism. GI = gastrointestinal. OR = operating room.

Table 2. Demographic data for each group. Average age is represented in years ± standard deviation. Gender distribution within the groups are presented with more females than males for total knee arthroplasty (TKA) and total hip arthroplasty (THA) groups. Table 3. The distribution of total joint arthroplasty complications (combining hip and knee arthroplasty) based on prophylaxis strategy presented as total cases and (percentage of total cases). Fisher’s Exact test. Table 4. The distribution of total knee arthroplasty (TKA) complications based on prophylaxis strategy presented as total cases and (percentage of total cases). Fisher’s Exact test. Table 5. The distribution of total hip arthroplasty (THA) complications based on prophylaxis strategy presented as total cases and (percentage of total cases). Fisher’s Exact test. Figure 1. Caseload distribution in each region for joint arthroplasty separating total hip arthroplasty (THA) and total knee arthroplasty (TKA). Figure 2. Regional variations and minimal and aggressive prophylactic strategies. Aggressive DVT prophylaxis strategies were significantly more common in every region (p<0.0001).

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Adam Boissonneault, M.B.Ch.B., PGY-3 EDUCATION Emory University School Of Medicine, Department Of Orthopaedics Atlanta, Ga 2015- Present Orthopaedic Surgery Resident PGY-3 • Bubba and Bwana Award – Outstanding PGY-2 resident Trinity College Dublin, School Of Medicine Dublin, Ireland Bachelor in Medicine, Bachelor of Surgery, Bachelor in Obstetrics: Honors 2010- 2015 University Of Pennsylvania Philadelphia, PA Post-Baccalaureate in Pre-Medicine; 2008-2009

Villanova University Villanova, PA Bachelor of Arts in English; 2002-2006 RESEARCH EXPERIENCE

EMORY UNIVERSITY SCHOOL OF MEDICINE, DEPARTMENT OF ORTHOPAEDICS Atlanta, GA Grady Memorial Hospital / Emory University Orthopaedic and Spine Hospital 2015- Present Contributed to research related to novel radiographic imaging for femoral anteversion, geriatric fracture care, and acute care in the polytraumatized patient • Constructed geriatric hip fracture and also acetabular / pelvic fracture database for Level I trauma

center PUBLICATIONS AND PRESENTATIONS Peer-reviewed publications:

Boissonneault A, Hiranaka T, Roberson JR, Bradbury TL. A Validated Single-View Radiographic Alternative to Computed Tomography for the Measurement of Femoral Anteversion: A Method-Comparison Study. J Arthroplasty. 2017 Mar;32(3):1018-1023.

Boden A, Staley C, Boissonneault A, Boden S, Schenker M. Emotional Intelligence in Medical Students is Inversely Correlated with USMLE Step 1 Score: Is there a Better Way to Screen Applicants? Journal of Medical Education. Accepted Februrary 2018.

Boissonneault A, Lynch JA, Wise B, Segal NA, Gross KD, Murray DW, Nevitt MC, Pandit HG. Association of hip and pelvic geometry with tibiofemoral osteoarthritis: Multicenter Osteoarthritis Study (MOST). Osteoarthritis Cartilage 2014, DOI 10.1016/j.joca.2014.06.010.

Boissonneault A, Pandit H, Pegg E, Jenkins C, Gill H, Dodd C, Gibbons C, Murray D. No difference in survivorship after unicompartmental knee arthroplasty with or without an intact anterior cruciate ligament. Knee Surg Sport Tra, 2012, DOI 10.1007/s00167-012-2101-8.

Podium presentations:

Boissonneault A, Staley C, Roorbach M, Erwood A, Johnson R, Maceroli M, Schenker M. Impact of prolonged skeletal traction in patient with acetabular fractures. Orthopaedic Trauma Association (OTA) Annual Meeting, Orlando FL, October 2018.

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Boissonneault A, Bellamy T, Labib S. Release of tibialis posterior muscle osseofascial sheath for chronic exertional compartment syndrome leads to improved outcomes: impact on long-term results. American Orthopaedic Foot and Ankle Society (AOFAS) Annual Meeting, Boston MA, July 2018.

Boissonneault A, Staley C, Roorbach M, Erwood A, Maceroli M, Schenker M. Use of closed suction drainage in acetabular fracture surgery is an independent risk factor for allogeneic blood transfusion. Southern Orthopaedic Association (SOA) Annual Meeting, Palm Beach FL, July 2018.

Wilson J, Boissonneault A, Schwartz A, Staley C, Schenker M. Malnutrition Is Associated with Frailty and Post-Operative Complications in Hip Fracture Patients. American Academy of Orthopaedic Surgeons (AAOS) Annual Meeting, New Orleans LA, March 2018.

Boissonneault A, Schwartz A, Wilson J, Staley C, Schenker M. Impact of Co-management Care Models on 30-day Morbidity and Mortality in Patients with Hip Fractures: Experience from a Large, Urban Level I Trauma Center. Southern Orthopaedic Association (SOA) Annual Meeting, Palm Beach FL, July 2018. Boissonneault A, Staley C, Roorbach M, Erwood A, Johnson R, Maceroli M, Schenker M. Early Allogeneic Blood Transfusion is an Independent Risk Factor for Development of Acute Respiratory Distress Syndrome in Patients with Pelvic Trauma. Southern Orthopaedic Association (SOA) Annual Meeting, Palm Beach FL, July 2018.

Broggi M, Boissonneault A, Staley C, Reisman W, Schenker M. Increased operating turnover time: maybe we should stop blaming anesthesia? Southern Orthopaedic Association (SOA) Annual Meeting, Palm Beach FL, July 2018.

Wilson J, Staley C, Boden A, Boissonneault A, Schwartz A, Schenker M. It’s Heating Up: Orthopaedic Trauma Consult Volume is Significantly Correlated with Daily Weather. Southern Orthopaedic Association (SOA) Annual Meeting, Palm Beach FL, July 2018.

Boissonneault A, Lynch JA, Wise B, Segal NA, Gross KD, Nevitt MC, Murray DW, Pandit HG. Association of tibiofemoral osteoarthritis with hip geometry: Multicenter Osteoarthritis Study (MOST). Combined Meeting of Orthopaedic Research Societies (CORS) Annual Meeting, Venice, Italy, October 2013.

Boissonneault A, Pandit H, Pegg E, Jenkins C, Gill H, Dodd C, Gibbons C, Murray D. Oxford UKR in the cruciate deficient knee. Oxford Global Knee Conference: Masters Symposium, Oxford, UK, September 2012.

Poster presentations:

Boissonneault A, Staley C, Johnson R, Maceroli M, Schenker M. Post-operative allogeneic blood transfusion in patients with pelvic and acetabular trauma: are we really treating an unresolved traumatic coagulopathy? Orthopaedic Trauma Association (OTA) Annual Meeting, Orlando FL, October 2018 Boissonneault A, Schwartz A, Staley C, Wilson J, Schenker M. The association between frailty and 30-day morbidity and mortality in patient with intertrochanteric femur fractures. Orthopaedic Trauma Association (OTA) Annual Meeting, Orlando FL, October 2018; Southern Orthopaedic Association (SOA) Annual Meeting, Palm Beach FL, July 2018.

Boissonneault A, Staley C, Roorbach M, Erwood A, Johnson R, Maceroli M, Schenker M. Early allogeneic blood transfusion is an independent risk factor for development of acute respiratory distress syndrome in patients with pelvic trauma. Orthopaedic Trauma Association (OTA) Annual Meeting, Orlando FL, October 2018. Boissonneault A, Staley C, Roorbach M, Erwood A, Maceroli M, Schenker M. Use of closed suction drainage in acetabular fracture surgery is an independent risk factor for allogeneic blood transfusion. Orthopaedic Trauma Association (OTA) Annual Meeting, Orlando FL, October 2018.

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Boden A, Staley C, Boissonneault A, Boden S, Schenker M. Emotional Intelligence in Medical Students is Inversely Correlated with USMLE Step 1 Score: Is there a Better Way to Screen Applicants? American Orthopaedic Association (AOA) CORD, Bi-annual meeting, Boston MA, June 2018.

Boissonneault A, Lynch JA, Wise BL, Segal NA, Gross KD, Murray DW, Nevitt MC, Pandit HG. Integrative assessment of frontal plane alignment of the hip and knee among subjects with and without knee osteoarthritis: the MOST study. Osteoarthritis Research Society International (OARSI): World Congress on Osteoarthritis, Paris, France, April 2014. Boissonneault A, Hiranaka T, Murray DW, Pandit HG. Variations in femoral anteversion and tibial torsion influence knee alignment in subjects with knee osteoarthritis. Orthopaedic Research Society (ORS) Annual Meeting, New Orleans, March 2014.

Boissonneault A, Pegg E, Murray D, Pandit H. Does native hip morphology predetermine the pattern of knee osteoarthritis? Orthopaedic Research Society (ORS) Annual Meeting, San Antonio, January 2013.

Boissonneault A, Pandit H, Pegg E, Jenkins C, Gill H, Dodd C, Gibbons C, Murray D. Does anterior cruciate ligament deficiency preclude unicompartmental arthroplasty? Orthopaedic Research Society (ORS) Annual Meeting, San Francisco, February 2012.

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Impact Of Closed Suction Drainage After Surgical Fixation Of Acetabular Fractures Adam R. Boissonneault, M.B.Ch.B., Michael Maceroli, MD, Madeline Roorbach, BA, Amalie A Erwood, BS, Zachary J. Grabel MD, Christopher Staley, BS, Thomas Moore Jr, MD, William Reisman, MD, Mara Schenker, MD

Abstract

Introduction. The purpose of the present study was to evaluate the prevalence of closed suction drainage after a Kocher-Langenbeck (K-L) approach for surgical fixation of acetabular fractures and to determine the impact of use of drains on outcomes.

Methods. This retrospective study reports on 171 consecutive patients that presented to a single Level I trauma center for treatment of an acetabular fracture between January 1, 2013 and December 31, 2016. Medical records were reviewed to evaluate the use of closed suction drains. The primary outcomes measures were rate of packed red blood cell (PRBC) transfusion and length of hospital stay (LOS). Secondary outcome measures were 30-day post-operative superficial wound complication and 1-year deep infection rates.

Results. Of the 171 patients included in this study, 140 (82%) patients were treated with drains. There was a significant association between the use of closed suction drainage and post-operative blood transfusion rate (p=0.002). Thirty-five patients (25%) treated with drains required a post-operative blood transfusion compared to 0% in the no drain cohort. For every additional drain that was placed, the odds of receiving a blood transfusion doubled (p=0.002). Use of closed suction drainage was associated with a significantly longer LOS (p=0.015), and no difference in wound complication or deep infection rates.

Conclusion. The use of closed suction drains for treatment of acetabular fractures using a K-L approach is associated with increased rates of blood transfusion and increased length of hospital stay, with no impact on surgical site infection rates. The results of this study suggest against routine drain usage in acetabular surgery.

Introduction

Surgical exposure for open reduction and internal fixation of acetabular fractures is dictated by fracture morphology.1-7 The Kocher-Langenbeck (K-L) approach is ideal for surgical fixation of the majority of acetabular fractures, specifically those involving the posterior wall, posterior column, and transverse patterns with predominately posterior displacement.2-9 Closed suction drainage is commonly utilized for post-operative wound management with the K-L approach to prevent hematoma formation. However, despite the theoretical advantages of closed suction drainage, there is minimal published evidence to support its routine use.10

The rationale for closed suction drainage is to eliminate dead space and decrease the rate of post-operative wound complications including hematoma and infection. Despite these proposed advantages, the use of closed suction drainage has been extensively examined in posterior surgical approaches for adult reconstruction patients with no proven benefit.10, 11-17 Similar results have been reported in the orthopaedic spine and trauma literature.18-21 Furthermore, there is suggestion that the use of drains may be detrimental, as illustrated by significantly increased blood transfusion rates in arthroplasty patients managed with drains.15-16 No clinical studies have evaluated the association of closed suction drainage with blood transfusion in operative acetabulum fractures and it is unclear if the results from elective arthroplasty would translate to trauma patients.

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Although there are no published data on current rates of drain usage in the trauma population, anecdotally, such practice continues to be routine amongst orthopaedic traumatologists, including at our own institution. The purpose of the present study was to evaluate the prevalence of closed suction drainage after a K-L approach for surgical fixation of acetabular fractures and to determine whether such use was related to post-operative allogeneic blood transfusion rates and length of hospital stay (LOS). Secondary outcome measures included 30-day superficial wound complication and 1-year deep infection rates. We hypothesized that the use of closed suction drains would be associated with increased rates of blood transfusion and an increased length of hospital stay, with no difference in short-term wound complications.

Materials and Methods

Patient selection. This retrospective observational study reports on patients that presented to a single American College of Surgeons – verified Level I trauma center for treatment of an acetabular fracture between January 1, 2013 and December 31, 2016. After institutional review board approval was obtained, medical records were queried for the 275 consecutive patients that were identified as available for inclusion in this study. Patients were excluded if they had combined acetabular and pelvic ring injuries (n=40), were treated percutaneously or with anterior or extensile surgical exposure (n=56), presented with a Morell-Lavalée lesion (n=5), or underwent simultaneous acute total hip arthroplasty (n=3). The final patient population consisted of 171 consecutive patients that underwent a K-L approach for surgical fixation of an acetabular fracture.

Data inclusion. Medical records including operative reports and inpatient progress notes were reviewed to evaluate the use of closed suction drains. Use of a drain, total number of drains utilized, and daily drain output was recorded. The primary outcomes measures were rate of packed red blood cell (PRBC) transfusion and LOS. The rate and total number PRBC units transfused was recorded. Our secondary outcome measures were 30-day post-operative superficial wound complication with or without unanticipated return to the operating room and 1-year rate of deep infection requiring operative debridement. Admission laboratory information was also collected, including hemoglobin (Hb), international normalized ratio (INR), and injury severity score (ISS). Acetabular fractures were classified based on the AO/OTA system after review of anterior-posterior (AP) and Judet radiographs as well as preoperative computed tomography (CT) imaging.22

Surgical protocol. All operations were performed using a standard K-L approach by an orthopaedic traumatologist (WR, TMJ, MS). The use of closed suction drainage at our institution is largely based on surgeon preference. Two author surgeons (WR, MS) routinely use multiple (2-3) closed suction drains placed in deep and superficial tissue planes. One author surgeon (TMJ) routinely uses no drains or one placed deep to the iliotibial band. Drain output was recorded every nursing shift (every 8 hours). Standard drain removal protocol was drain output less than 30 milliliters over an 8-hour time period.

Statistical analysis. The distribution of continuous numerical data including demographic and laboratory data was examined in descriptive histograms and box plots, and a Kolmogorov Smirnov test was used to confirm a normal distribution. A chi-squared test was used for nominal data to compare post-operative transfusion and wound complication to drain utilization. An independent samples t-test was used to compare laboratory and surgical data between patients who received drains and those who did not. An analysis of variance was used to compare differences in number of drains used by surgeon, and mean EBL by number of drains used; a post-hoc Bonferroni analysis was performed to explore pair-wise differences. Multi-variate logistic regression was performed to evaluate the odds of receiving a post-operative blood transfusion whether closed suction drainage was used. Co-variates included in the regression model included Hb, EBL, and ISS. All statistical analyses were performed with Stata statistical software (StataCorp. 2015. Stata Statistical Software: Release 14. College Station, TX: StataCorp LP.).

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Results

Prevalence of drain use. Of the 171 patients included in this study, 140 (82%) patients were treated with drains. There was a significant difference in number of drains used between surgeons (p<0.001) (Table 1). The mean number of drains used by surgeon 1 was 0.6 compared to 2.2 and 2.0 drains for surgeons 2 and 3, respectively (p<0.001). There was no significant difference in patient factors between those treated with drains and those without. The mean age for patients treated with drains was 36 (standard deviation (SD) 10) years compared to 34 (SD 10) years for those without drains (p=0.324). The mean BMI for those treated with drains was 31 (SD 18) kg/m2 compared to 28 (5) kg/m2 for those without drains (p=0.291).

Drain usage by fracture type. Of the 171 patients, there were 73 posterior wall (62-A1), 53 transverse posterior wall (62-B1a2), 22 posterior column posterior wall (62-A2.3), 12 T-type (62-B2), 7 transverse (62-B1a1), 2 posterior column (62-A2), and 2 anterior column posterior hemitransverse fractures (62-B3). The two anterior column posterior hemitransverse fractures were patterns with a stable anterior column segment and predominant posterior displacement of the transverse segment. There was no significant association between number of drains used and fracture morphology (p=0.085) (Table 2). For simple posterior wall fractures, 34 patients had 0 or 1 drain placed versus 39 patients that had 2 or 3 drains placed.

Drain usage versus EBL. The mean (SD) reported EBL was 254 (129) mL, 308 (164) mL, and 519 (297) mL for surgeons 1-3 respectively. There was a significant difference in reported EBL between surgeon 3 and surgeons 1 and 2 (p<0.001) (Table 3). For surgeon 1, there was a significant association between number of drains used and EBL (p=0.026), with an average of 84mL additional blood loss in patients treated with 1 drain compared to no drains. For surgeon 2 and 3, there was no significant association between number of drains used and EBL.

Prevalence of blood transfusion. Of the 171 patients in this study, 35 (20%) received a post-operative allogeneic blood transfusion. Patients that received a blood transfusion had a significantly lower mean Hb on admission (p<0.001) (Table 4). Patient that received a blood transfusion also had a significantly higher EBL (p=0.002) and ISS (p<0.001) (Table 4). There was no difference in admission INR between patient that received a blood transfusion and those that did not. The mean hemoglobin at time of blood transfusion was 7.5 (SD 1.4) g/dL. The threshold for transfusion in this study was uniform in the study population such that there was no significant difference in post-operative Hb before transfusion between surgeons (p=0.110).

Association between drain usage and blood transfusion. There was a significant association between the use of closed suction drainage and post-operative blood transfusion rate (p=0.002). Thirty-five patients (25%) treated with drains required a post-operative blood transfusion compared to 0% in the no drain cohort. After controlling for admission Hb, ISS, and EBL, patients treated with drains were 22 times more likely to receive a blood transfusion (OR 22.2, 95% confidence interval (CI) 1.0-498.7; p=0.049). For every additional drain that was placed, the odds of receiving a blood transfusion doubled (OR 2.0, 95%CI 1.3-3.1; p=0.002). Amongst simple posterior wall fractures only, the odds of receiving a blood transfusion nearly tripled for every additional drain that was used (OR 2.7, 95%CI 1.3-5.8; p=0.008).

Drain utilization and length of hospital stay. The mean LOS for patients treated with drains was 11 (SD 7) days compared to 8 (SD 4) days for those that were not (p=0.015). The mean LOS for patients that received a blood transfusion was 15 (SD 8) days compared to 9 (5) days for those were not (p<0.001).

Drain utilization and surgical site infection rates. The total number of 30-day superficial wound complications in the entire cohort was 3 (1%). All wound complications occurred in patients that were treated with closed suction drains. The difference between groups was not statistically significant (p=0.411). All three patients were placed on a short course of oral antibiotics. Only one patient in the entire cohort was found to have a deep hardware associated infection that required operative management. The single patient with deep infection was treated with 3 drains at his index procedure.

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Discussion and Conclusions

The present study examined the prevalence and associated impact of closed suction drainage after acetabular surgery at a high-volume level 1 trauma center. The use of drains was associated with an increased prevalence of post-operative blood transfusion and longer length of hospital stay. Furthermore, there were no differences in wound complications or deep infection rates between patients treated with or without drains. As demonstrated in our study population, the use of drains after a K-L approach is often based on surgeon preference and routine protocols and not specifically related to surgical blood loss or fracture morphology.

The increased transfusion rates in orthopaedic patients treated with drains in our study are consistent with previous reports in the arthroplasty and spine literature.15-16,18 Our study also confirms previous works in the trauma and arthroplasty literature that illustrate the association between increased EBL and ISS with increased blood transfusion rates, and also decreased admission Hb with increased blood transfusion rates.23-29 Notably, the multivariate logistic regression model in the present study revealed that independent of these previously identified risk factors for blood transfusion, the odds of receiving a blood transfusion was still over twenty times higher in patients treated with drains.

The current study revealed that omission of closed suction drainage had no association with early (30-day) or late (1-year) infection rates. This finding is supported by Hsu et al. 30, who also reported drain use had no impact on infection rates in patients who underwent acetabular surgery using the K-L approach. Although the theoretical benefit of closed suction drainage is to prevent hematoma formation and potential wound breakdown, multiple studies have shown no difference in clinically significant hematoma formation irrespective of drain use.19,21 These findings suggest that judicious omission of closed suction drains in posterior approach acetabular surgery is safe when done in appropriate patients.

Current trauma and arthroplasty literature has identified closed suction drainage as a risk factor for increased length of hospital stay.23-24, 29, 31-33 This finding is supported in the present study with a significant association between presence of drains and longer LOS. Due to the retrospective nature of the study, we cannot confirm causation but would suggest that the increased length of stay is likely sequela from the higher blood transfusion rates in these patients. In addition, patients with multiple drains may be more hesitant to mobilize, and it is possible that the presence of multiple drains may delay discharge by impeding physical therapy.

To our knowledge, our study is the first to describe the association between the number of closed suction drains utilized and prevalence of post-operative blood transfusion. Our results demonstrated that for every additional drain that is placed, the odds of requiring a blood transfusion doubles. For simple posterior wall fractures, the odds of blood transfusion for every additional drain that was used nearly tripled. Extrapolation of this data illustrates that compared to patients that receive only 1 drain, the odds of receiving a blood transfusion is 9 times higher in those that receive 3 drains. One potential explanation for this finding may be that the increased suction pressure creates a higher flow state and prevents stable clot formation. As a result, the duration and amount of effective total blood loss is increased, as well as the risk of blood transfusion. Should one decide to use closed suction drainage after fixation of acetabular fractures, these results would support a ‘less is more’ approach to drain utilization in an effort to reduce risk of blood transfusion and decrease LOS.

There are several potential limitations to this study. Most notably, due to the retrospective nature of the study, there was no strict criteria for the decision to omit or place a closed suction drain. However, our data clearly demonstrates that drain use was related to surgeon preference and not necessarily surgical blood loss or fracture morphology. In fact, we specifically analyzed these variables and noted that there was no significant association between drain placement and intra-operative blood loss, patient BMI, or fracture morphology. Furthermore, patients with associated soft tissue injuries that would be treated with closed suction drainage (n=5) as a standard of care were omitted from our analysis to create as homogenous a population as possible.

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Additionally, this investigation was conducted at a single institution and indications for transfusion may differ from other centers. However, transfusion criteria amongst the cohort evaluated in this study was uniform and did not vary significantly between surgeons.

Conclusion

The use of closed suction drains for treatment of acetabular fractures using a K-L approach is associated with increased rates of blood transfusion and increased length of hospital stay, with no impact on surgical site infection rates. The results of this study suggest against routine drain usage in acetabular surgery. Notably, we are not recommending against drain utilization in all patients, but when drain placement is indicated for specific at-risk wounds, a more judicious approach should be taken. Continued prospective investigation is warranted to further validate this recommendation.

TABLES

Table 1. Drain utilization by surgeon

Surgeon

Drains (No.) 1 2 3 Total

0 30 1 0 31

1 37 7 1 45

2 1 53 11 65

3 0 29 1 30

Table 2. Drain utilization by fracture morphology

Drains (No.)

Fracture type 0 1 2 3 Total

PW 19 15 30 9 73

Trans + PW 3 14 22 14 53

PC + PW 5 11 4 2 22

T-type 1 3 4 4 12

Transverse 1 2 3 1 7

PC 1 0 1 0 2

AC PHT 1 0 1 0 2

PW – posterior wall; Trans + PW – transverse posterior wall; PC + PW – posterior column posterior wall; PC – posterior column; AC PHT – anterior column posterior hemitransverse

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Table 3. Association between drain utilization and EBL by surgeon

Number of drains (mean EBL(mL))

Surgeon 0 1 2 3 p-value*

1 207 291 300 -- p=0.026

2 150 186 322 321 p=0.147

3 -- 100 541 700 p=0.324

* Analysis of variance (ANOVA) test

Table 4. Risk factors for blood transfusion

Blood transfusion

No Yes p-value

Hb 13.8 12.3 p<0.001

INR 0.98 1.03 p=0.083

ISS 9.8 16.9 p<0.001

EBL 282.6 388.7 p=0.002

Hb – hemoglobin; INR – international normalized ratio; ISS – injury severity score; EBL – estimated blood loss

References: 1. Letournel E. Acetabulum fractures: classification and management. Clin Orthop Relat Res. 1980;(151):81-106. 2. Judet R, Judet J, Letoumel E. Fractures of the acetabulum: Classification and surgical approaches for open reduction. J Bone Joint Surg. 1964;46A:1615-1646. 3. Matta JM. Fractures of the acetabulum: Accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury. J Bone Joint Surg Am 1996;78:1632-45 4. Moed BR, Carr SE, Watson JT. Open reduction and internal fixation of posterior wall fractures of the acetabulum. Clin Orthop Relat Res 2000;377:57-67. 5. Moed BR, WillsonCarr SE, Watson JT. Results of operative treatment of fractures of the posterior wall of the acetabulum. J Bone Joint Surg Am 2002;84-A:752-8. 6. Cutrera NJ, Pinkas D, Toro JB. Surgical Approaches to the Acetabulum and Modifications in Technique. J Am Acad Orthop Surg 2015;23(10):592-603. 7. Matta JM, Merritt PO. Displaced acetabular fractures. Clin Orthop Relat Res. 1988 May;(230):83-97. 8. Magu NK, Rohilla R, Arora S et al. Modified Kocher-Langenbeck approach for the stabilization of posterior wall fractures of the acetabulum. J Orthop Trauma 2011;25:243-9. 9. Negrin LL, Seligson D. Results of 167 cases of acetabular fractures using the Kocher-Langenbeck approach: a case series. J Orthop Surg Res. 2017;26;12(1):66. 10. Parker MJ, Livingstone V, Clifton R, et al. Closed suction surgical wound drainage after orthopaedic surgery. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD001825. 11. Magee C, Rodeheaver GT, Golden GT, et al. Potentiation of wound infection by surgical drains. Am J Surg. 1976;131:547-9.

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12. Willett KM, Simmons CD, Bentley G. The effect of suction drains after total hip replacement. J Bone Joint Surg Br. 1988;70:607-10. 13. Jenny JY, Boeri C, Lafare S. No drainage does not increase complication risk after total knee prosthesis implantation: a prospective, comparative, randomized study. Knee Surg Sports Traumatol Arthrosc. 2001;9:299-301. 14. Niskanen RO, Korkala OL, Haapala J, et al. Drainage is of no use in primary uncomplicated cemented hip and knee arthroplasty for osteoarthritis: a prospective randomized study. J Arthroplasty. 2000;15:567-9. 15. Ovadia D, Luger E, Bickels J, et al. Efficacy of closed wound drainage after total joint arthroplasty. A prospective randomized study. J Arthroplasty. 1997;12:317-21. 16. Parker MJ, Roberts CP, Hay D. Closed suction drainage for hip and knee arthroplasty. A meta-analysis. J Bone Joint Surg Am 2004;86-A(6):1146-52. 17. Esler CN, Blakeway C, Fiddian NJ (2003) The use of a closed suction drain in total knee arthroplasty. A prospective, randomized study. J Bone Joint Surg Br 85:215–217. 18. Liu JM, Chen WZ, Fu BQ, et al. The use of closed suction drainage in lumbar spinal surgery: Is it really necessary?. World Neurosurg. 2016 Jun;90:109-115. 19. Waly F, Alzahrani MM, Abduljabbar FH, et al. The Outcome of Using Closed Suction Wound Drains in Patients Undergoing Lumbar Spine Surgery: A Systematic Review. Global Spine J 2015;5(6):479-85. 20. Tjeenk RM, Peeters MP, van den Ende E, et al. Wound drainage versus non-drainage for proximal femoral fractures. A prospective randomised study. Injury 2005;36(1):100-4 21. Lang GJ, Richardson M, Bosse MJ, et al. Efficacy of surgical wound drainage in orthopaedic trauma patients: a randomized prospective trial. J Orthop Trauma 1998;12(5):348-50. 22. Marsh JL, Slongo TF, Agel J, et al. Fracture and Dislocation Classification Compendium - 2007: Orthopaedic Trauma Association Classification, Database and Outcomes Committee. J Orthop Trauma. 2007;21 Supplement 10 pp: S1-S163. 23. Dolenc AJ, Morris WZ, Como JJ, et al. Limited Blood Transfusions Are Safe in Orthopaedic Trauma Patients. J Orthop Trauma. 2016 Dec;30(12):e384-e389. 24. Hsu JM, Hitos K, Fletcher JP. Identifying the bleeding trauma patient: predictive factors for massive transfusion in an Australasian trauma population. J Trauma Acute Care Surg. 2013 Sep;75(3):359-64. 25. Dunne JR1, Riddle MS, Danko J, et al. Blood transfusion is associated with infection and increased resource utilization in combat casualties. Am Surg. 2006 Jul;72(7):619-25; discussion 625-6. 26. Bini SA, Darbinian JA, Brox WT, et al. Risk Factors for Reaching the Post-Operative Transfusion Trigger in a Community Primary Total Knee Arthroplasty Population. J Arthroplasty. 2017 Dec 5. pii: S0883-5403(17)30941-5. doi: 10.1016/j.arth.2017.10.029. 27. Slover J, Lavery JA, Schwarzkopf R, et al. Incidence and Risk Factors for Blood Transfusion in Total Joint Arthroplasty: Analysis of a Statewide Database. J Arthroplasty. 2017 Sep;32(9):2684-2687. 28. King JJ1, Patrick MR, Schnetzer RE, et al. Multivariate Analysis of Blood Transfusion Rates After Shoulder Arthroplasty. J Surg Orthop Adv. 2017 Spring;26(1):40-47. 29. Saleh A, Small T, Chandran Pillai AL, et al. Allogenic blood transfusion following total hip arthroplasty: results from the nationwide inpatient sample, 2000 to 2009. J Bone Joint Surg Am. 2014 Sep 17;96(18). 30. Hsu JR, Stinner DJ, Rosenzweig SD, et al. Is there a benefit to drains with a Kocher-Langenbeck approach? A prospective randomized pilot study. J Trauma 2010;69(5):1222-5. 31. Bjerke-Kroll BT, Sculco PK, McLawhorn AS, et al. The increased total cost associated with post-operative drains in total hip and knee arthroplasty. J Arthroplasty 2014;29(5):895-9. 32. Klika AK, Small TJ, Saleh A, et al. Primary total knee arthroplasty allogenic transfusion trends, length of stay, and complications: nationwide inpatient sample 2000-2009. 33. Mistry JB, Gwam CU, Naziri Q, et al. Are Allogeneic Transfusions Decreasing in Total Knee Arthroplasty Patients? National Inpatient Sample 2009-2013. J Arthroplasty [published Online First: Epub Date].

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Zach Grabel, MD PGY-3 DUCATION Emory University School of Medicine, Department Of Orthopaedics Atlanta, Ga 2015- Present Orthopaedic Surgery Resident PGY-3 Brown University, Alpert Medical, Providence , Rhode Island Doctor of Medicine, May 2015 Alpha Omega Alpha Honor Society University Of Florida, Gainesville, FL Health and Human Performance; May 2011 PUBLICATIONS Grabel ZJ, Vitiligo: A Literature Review and Analysis of Variants in TYR Gene in

Multiplex Families. University of Florida Undergraduate Thesis Database, 2011.

Daniels AH, Grabel ZJ, DiGiovanni CW. ACGME Accreditation of Orthopaedic Surgery Subspecialty Fellowship Training Programs. J Bone Joint Surg Am. 2014 Jun4;96(11):e94.

Daniels AH, Bariteau JT, Grabel ZJ, DiGiovanni C. Prospective Analysis of a Novel Orthopedic Residency Advocacy Education Program. R I Med J. 2014 Oct 1;97(10):43-6.

Grabel ZJ, DePasse JM, Lareau CR, Born CT, Daniels AH. Intra-articular placement of an intraosseous catheter. Prehosp Disaster Med. 2014 Dec 8;30(1):1-4.

Vigneswaran HT, Grabel ZJ, Eberson CP, Palumbo MA, Daniels AH. Surgical treatment of adolescent idiopathic scoliosis in the United States from 1997 to 2012: an analysis of 20,346 patients. J Neurosurg Pediatr. 2015 Jun; 26:1-7. Albright TH, Grabel Z, DePasse JM, Palumbo MA, Daniels AH. Sexual and reproductive function in spinal cord injury and spinal surgery patients. Orthop Rev (Pavia). 2015 Oct; 7(3):5842

Johnson JP, Daniels AH, Grabel ZJ,, Miller SM, Eberson CP. Referral for adolescent idiopathic scoliosis by pediatric primary care providers. Clin. Pediatr (Phila). 2016 Jul 56(1):20-25.

Zachary J. Grabel; Robert A. Hart; Aaron P. Clark; Sara Heejung Park; Christopher I.Shaffrey; Justin K. Scheer; Justin S. Smith; Michael P. Kelly; J. Mason DePasse; Munish C. Gupta; Christopher P. Ames; Alan H. Daniels. Adult Spinal Deformity Knowledge inOrthopedic Spine Surgeons: Impact of Fellowship Training, Experience, and Practice Characteristics. Spine Deform. 2018 Jan;6(1):60-66.

Grabel ZJ, Armaghani SJ, Vu C, Jain A, Yoon ST. Variations in Treatment of C2 Fractures by Time, Age, and Geographic Region in the United States: An Analysis of 4818 Patients. World Neurosurg. 2018 May;113:e535-e41.

Grabel ZJ, Boden A, Segal DN, Boden S, Milby AH, Heller JG. The impact of prophylactic intraoperative vancomycin powder on microbial profile, antibiotic regimen, length of stay, and reoperation rate in elective spine surgery. Spine J. Accepted, In Press. Abstracts and Posters

Grabel ZJ, Stopka, C; Barwick, R; Delisle, T; Idica, J. “Can One Weekend of Volunteering Improve Self-Satisfaction?” published abstract, NCPERID Annual Conference Proceedings, Reston, VA, July 14-16, 2011, p 19.

Bariteau JT, Grabel ZJ, Daniels AH, DiGiovanni C. Prospective Analysis of a Novel Orthopaedic Residency Advocacy Education Program. AOA/COA Combined Annual Meeting, Montreal, QC, Canada, June 2014.

Bariteau JT, Grabel ZJ, Daniels AH, DiGiovanni C. Prospective Analysis of a Novel Orthopaedic Residency Advocacy Education Program. AAOS Annual Meeting, New Orleans, LA, March 2014.

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Daniels AH, Ames CP, Grabel ZJ, Smith JS, Hart R. The Variablity in Spine Surgery Procedures During Orthopaedic and Neurological Surgery Residency Training: An Analysis of ACGME Case Log Data. Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves, Phoenix, AZ, March 2015.

Daniels AH, Grabel ZJ, Vigneswaran H, Eberson CP, Palumbo MA. Surgical Treatment of Pediatric Spinal Deformity in the United States from 1997 to 2009: An Analysis of 22, 823 Patients. Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves, Phoenix, AZ, March 2015.

Grabel ZJ, Daniels AH, Palumbo MA, Vigneswaran H, Eberson CP. Postoperative Transfusion Rates, Complications, and Hospital Charges Following Surgical Treatment of Adolescent Idiopathic Scoliosis in the United States from 1997 to 2012. North American Spine Society Annual Meeting, Chicago, IL, October 2015.

Johnson J, Daniels AH, Miller S, Grabel ZJ, Eberson CP. Referral for Adolescent Idiopathic Scoliosis by Pediatric Primary Care Providers: Patterns of Referral and the Role of Insurance Status. North American Spine Society Annual Meeting, Chicago, IL, October 2015.

Segal DN, Grabel ZJ, Shi J, Gottschalk MB, Boden SD. The Impact of Insurance Coverage on Access to Orthopedic Spine Care. Eastern Orthopaedic Association 40th Annual Meeting, Miami, FL, October 2017.

Boissonneault AB, Maceroli M, Grabel ZJ, Roorbach M, Erwood A, Staley C1,Schenker ML. Use of closed suction drainage in acetabular fracture surgery is an independent risk factor for allogeneic blood transfusion. OTA Annual Meeting, Orlando, FL, October 2018. PODIUM PRESENTATIONS Wallace MP, McCormack W, Herbstman D, Grabel ZJ, Genetics of Vitiligo. Presented atAmerican Vitiligo Research Foundation Conference, Clearwater, FL, July, 2011.

Grabel ZJ, Hart RA, Clark AP, Shaffrey CI, Scheer JK, Smith JS, Kelly MP, Ames CP, Daniels AH. Adult spinal deformity knowledge in orthopaedic spine surgeons: impact of fellowship training and practice experience. AAOS Annual Meeting, Orlando, FL, March 2016.

Segal DN, Grabel ZJ, Wilson J, Shi J, Milby AH, Hutton WC, Rhee JM. Total Disc Replacement Adjacent to a Multilevel Fusion in the Cervical Spine: A Biomechanical Study. NASS Annual Meeting, Los Angeles, CA, September 2018.

Grabel ZJ, Segal DN, Boden A, Boden S, Milby AH, Heller JG. The impact of prophylactic intraoperative vancomycin powder on microbial profile, antibiotic regimen, length of stay, and reoperation rate in elective spine surgery. SRS Annual Meeting, Bologna, Italy, October 2018.

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The Impact Of Prophylactic Intraoperative Vancomycin Powder On Microbial Profile, Antibiotic Regimen, Length Of Stay, And Reoperation Rate In Elective Spine Surgery Zachary J. Grabel, MD; Allison Boden, BA; Dale N. Segal, MD; Stephanie Boden, BA; Andrew H Milby, MD; John G. Heller, MD ABSTRACT

Background context: There is growing concern that the microbial profile of surgical site infection (SSI) in the setting of prophylactic vancomycin powder may favor more resistant and uncommon organisms.

Purpose: To demonstrate the impact of prophylactic intraoperative vancomycin powder on microbial profile, antibiotic regimen, length of stay, and reoperation rate in spine surgical site infection.

Study Design/Setting: Retrospective cohort study.

Patient Sample: The study included 115 post-operative spine patients who were required to return to the operating room for surgical site infection.

Outcome Measures: The outcome measures were microbial profile, reoperation rate, antibiotic regimen, and length of stay (LOS) for patients with postoperative spine infection who either did (treated) or did not (untreated) receive prophylactic vancomycin powder during their index procedure.

Methods: A retrospective review of patients who underwent posterior thoracic and/or lumbar spine surgery between 2010 and 2017 was conducted. Those undergoing surgical treatment of SSI were identified, and patients were divided into two groups - those who were treated with intra-operative vancomycin (treated) and those who were not (untreated). The organism profile for each group was compared. The average length of stay, reoperation rate, and number of patients requiring more than one antibiotic were calculated for each patient in both groups.

Results: There were 5,909 procedures performed. 115 SSIs were identified, resulting in a 1.9% infection rate. Prophylactic vancomycin powder was used in the index procedure for 42 of those cases. 23.8% of cultures in the vancomycin group were polymicrobial and 16.7% were gram negative compared to 9.6% (p=0.039) and 4.1% (p=0.021) in the untreated group, respectively. In the vancomycin-treated group, 26.1% of patients underwent repeat irrigation and debridement (I&D) compared to 38.4% in the untreated group (p=0.184). The percentage of patients in the treatment and untreated group who required more than one antibiotic was 26.0% and 26.1%, respectively (p=0.984). Mean LOS in the treatment group was 8.0 versus 7.9 for the untreated group (p=0.945)

Conclusions: In this series, vancomycin powder was associated with a higher prevalence of gram negative and polymicrobial organisms in patients that ultimately developed post-operative SSI. However, this did not adversely affect the need for multiple reoperations, antibiotic regimen, or length of stay for these patients.

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Introduction

Surgical site infection (SSI) following spine surgery is a clinically devastating and resource-intensive complication. The incidence of postoperative spine SSI ranges from 0.7 to 12%.1-3 Prior literature has demonstrated an additional cost of $33,705 associated with each spine SSI.4 The prophylactic use of intraoperative vancomycin powder has been shown in several series to be effective in decreasing the rate of post-operative infection in spine surgery.5-11

While the use of intraoperative vancomycin may result in a lower incidence of SSI, there is growing concern that when an SSI does occur in this setting, the microbial profile of these SSIs may favor more resistant and uncommon organisms. A recent study examined positive cultures in postoperative SSI after spine deformity surgery in which intraoperative vancomycin was used in all cases. This investigation revealed the majority of cultures were gram negative and polymicrobial.12 Another single institution study similarly examined the microbial trends in patients with post-operative spine SSI (all regions and indications) who were treated with prophylactic local vancomycin and suggested an increase in gram negative and polymicrobial cultures.13

The purpose of this study was two–fold. First, we sought to compare the microbial profile of SSI in treated patients (intraoperative local vancomycin used) versus untreated patients (no local vancomycin) who underwent elective thoracic and/or lumbar decompression with or without fusion. Second, it examined the effects of local vancomycin powder on the extent of required treatment, including number of reoperations, complexity of antibiotic regimen, and length of stay (LOS). To our knowledge, this has not been documented in the literature.

Methods

Patient Selection

Institutional review board approval was obtained prior to initiation of this study. A retrospective review of patients who underwent posterior thoracic and/or lumbar spine surgery with or without fusion between 2010 and 2017 was conducted. Exclusion criteria included cervical spine procedures, procedures performed through a lateral or anterior approach, and infection as an indication for surgery.

Amongst this group, a query was performed to identify patients with surgical site infection. We defined a clinically-significant SSI by the need to return to the operating room for an irrigation and debridement procedure. The decision to proceed was made at the discretion of the attending surgeon based on a combination of clinical criteria. Criteria included: wound drainage, wound dehiscence, fevers, evidence of infection on imaging, and elevated infectious laboratory values such as erythrocyte sedimentation rate, C-reactive protein, and white blood cell count. Amongst this cohort of patients with SSI, patient demographics, comorbidities, previous spine surgery, the use of intraoperative vancomycin, complications, and the onset of SSI after index procedure were recorded.

Surgical Details

At our institution, it is standard practice for all patients to receive pre-operative and post-operative prophylactic antibiotics. Typically, this consists of weight based intravenous (IV) cefazolin within 1 hour of incision and every 8 hours for 24 hours after surgery. Patients with penicillin allergies receive either IV clindamycin or vancomycin. Subfascial drains are used in most cases but this is based on surgeon preference. Distribution and dosing of vancomycin powder was variable amongst surgeons, but typical use included wide dispersal of one gram of vancomycin powder throughout the wound immediately prior to fascial closure.

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Outcome Measures and Statistical Analysis

Patients were divided into two groups – those who were treated with local intraoperative vancomycin (treated) and those who were untreated (non-vancomycin cohort). The organism profile for each group was compared. The average length of stay, reoperation rate, and number of patients requiring more than one antibiotic were calculated for each patient in both groups. Patients in the treated and untreated group were then further categorized by culture result (gram positive, gram negative, polymicrobial, fungal, no growth). The average length of stay, reoperation rate and number of patients requiring more than one antibiotic were compared by culture type between the treated and untreated group. Chi square analysis and 2-tailed t test were used. Multivariable logistic regression analysis was performed to control for discrepancies in patient characteristics amongst the vancomycin-treated group and the untreated group. Statistical significance was defined as a P value less than 0.05.

Results

There were 5,909 thoracic and/or lumbar decompression with or without fusion procedures performed between 2010 and 2017. 115 SSIs were identified, resulting in a 1.9% infection rate. Amongst the SSI cohort, 42 patients had received intraoperative vancomycin. Smoking history, history of diabetes, number of comorbidities, number of post-operative complications, and onset of SSI were not statistically different between the two groups. Mean BMI of patients in the vancomycin group was 32.1 compared to 29.1 in the untreated cohort (p=0.046). The majority of patients in the treatment group underwent fusion procedures (78.6%) as opposed to the untreated group (38.4%)(p=0.0003). Only 26.2% of the patients in the vancomycin-treated group had a history of prior spine surgery compared with 46.6% in the untreated group (p=0.031) (Table 1). Multivariable logistic regression analysis results are illustrated in Table 2.

Overall, the most common organism cultured was methicillin-sensitive staphylococcus (Staph) aureus (MSSA) (36.5%). Polymicrobial and gram negative organisms represented 14.8% and 8.7% of cultures, respectively. There were 28 cases with no growth from intraoperative cultures (24.3%). Coagulase-negative staphylococcus represented 6.1% of organisms. Escherichia coli was the most common gram negative culture (Table 3).

26.1% of culture-positive infections in the vancomycin group were gram positive organisms, all of which were Staph species. In the untreated group, 64.4% of positive cultures were gram positive and Staph infections represented 57.5% of infections (p=0.001). 23.8% of cultures in the vancomycin group were polymicrobial and 16.7% were gram negative compared to 9.6% (p=0.039) and 4.1% (p=0.021) in the untreated group, respectively. There were two cultures positive for fungus in the non-vancomycin group and none in the treatment group. Approximately one third (33.3%) of the cultures in the treatment group revealed no-growth compared to 19.1% in the non-vancomycin group (p=0.089)(Table 4).

In the vancomycin-treated group, 26.1% of patients required an additional irrigation and debridement (I&D) compared to 38.4% in the untreated group (p=0.184). The percentage of patients in the treatment group and non-vancomycin group who required more than one antibiotic was similar (26.0% vs. 26.1%, respectively; p=0.984). Mean length of stay for the vancomycin treatment group was 8.0 versus 7.9 for the untreated group (p=0.945) (Table 5).

When broken down by culture type, 18.2% of gram positive infections in the vancomycin group required repeat I&D and more than one antibiotic compared to 44.7% (p=0.106) and 21.3% (p=0.819) of gram positive infections in the untreated group, respectively (Table 6A, 6B). Three of the gram negative infections in the vancomycin treatment group required additional reoperations versus zero in the untreated group. Polymicrobial infections in the vancomycin group required repeat I&D and treatment with more than on antibiotic 60% of the time, respectively, compared with repeat I&D rate of 85.7% (p=0.252) and treatment with multiple antibiotics in 100% (p=0.628) of patients in the untreated group with polymicrobial infection (Table 6A, 6B). Polymicrobial

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infection resulted in the greatest mean length of stay in both the vancomycin-treated and untreated group: 10.3 and 15.1 days, respectively (p=0.108) (Table 6C).

Discussion

The application of intraoperative vancomycin powder in spine surgery has been reported by many studies to decrease the rate of surgical site infection.5-11 O’Neil et al7 evaluated the infection rate of patients who underwent spine arthrodesis for traumatic spine injuries. The cohort who received intraoperative vancomycin had a 0% rate of infection and the control group had a 13% rate of SSI. Sweet et al5 demonstrated a 10-fold decrease in infection rate with intra-operative vancomycin in patients who underwent posterior thoracolumbar fusions. Furthermore, Strom et al8 demonstrated a similar decrease rate in infection with use of intraoperative vancomycin in patients who underwent posterior cervical fusions. Chiang et al9, through meta-analysis, and Heller10 et al, through retrospective investigation, specifically reported a decreased rate of Staph aureus associated SSIs when intraoperative vancomycin was used. We sought to determine whether SSI in patients who received intraoperative vancomycin may favor more virulent organisms. In addition, this study examined the impact that intraoperative vancomycin has on reoperation rate, antibiotic regimen and length of stay.

The overall infection rate in the present study was 1.9%, which is consistent with prior studies.4,5,14-16 Staph aureus was the most common organism isolated amongst all SSIs in our study. This is consistent with the results of Amir Abdul-Jabbar et al’s14 investigation, which examined the pathogen profile amongst 239 spine infections (all spine regions). Interestingly, MSSA was significantly more prevalent in the untreated cohort but there was no difference in prevalence of Coagulase-negative Staph and methicillin-resistant Staph aureus (MRSA) amongst the two cohorts. This may be attributed to the relatively small number of Coagulase-negative Staph (7) and MRSA (3) SSIs compared to MSSA (42). This investigation revealed that gram negative infections and polymicrobial infections were significantly more prevalent in patients who received intraoperative local vancomycin compared to those who did not. Adogwa et al12 and Ghobrial et al13 suggested gram negative infections were more common amongst patients who received prophylactic vancomycin powder. However, neither of these studies included a control or untreated cohort. In addition, we demonstrated that there was a significantly higher proportion of isolated gram positive cultures in the untreated cohort compared to those who received vancomycin. We believe this phenomenon is secondary to vancomycin’s prophylactic effect against gram positive organisms. However, it must be noted that more patients in the vancomycin-treated cohort underwent a fusion procedure (Table 1) and multivariable analysis demonstrated that a fusion procedure is independently associated with a lower odds of gram positive culture in a SSI (Table 2), although there is no clear explanation for this. Furthermore, more patients in the untreated group had a history of prior spine surgery, which was found to be an independent risk factor for gram positive culture in those with SSI (Table 2). Therefore, patients with a history of previous spine surgery who are not treated with vancomycin powder may be especially susceptible to a gram positive organism should they develop an SSI.

The overall no-growth rate in our study (24.2%) is consistent with prior studies.12,13 In contrast to the vancomycin arm in our study, which demonstrated a 33.3% no growth rate, Amir Abdul-Jabbar et al14 revealed a negative culture rate of 2.9% and none of their patients received vancomycin powder. One possibility for a relatively high no growth rate in the vancomycin arm of our study is that high concentrations of local vancomycin suppressed culture growth. On the contrary, it is possible that we have a cultural bias that favors returning to the operating room in the case of a persistently draining wound, whether infected or otherwise. The notion is that a draining wound not only allows entry to bacteria but the existing hematoma/seroma is a fertile culture medium. This may also explain the relatively large percent of cultures without growth in our investigation and aforementioned studies.

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Interestingly, there was no significant difference in the need for multiple antibiotics or mean length of stay between the vancomycin-treated group and the untreated cohort. There was a pattern towards increased reoperation rate for those who did not receive intraoperative vancomycin, however this was not statistically significant. It is possible that, with a larger sample size, this phenomenon becomes significant in which case another benefit of local application of vancomycin would be that it lowers reoperation rate in those who develop SSI. The reoperation rate, antibiotic regimen, and average LOS were compared by culture type between vancomycin-treated patients and the untreated group to determine if intraoperative vancomycin had an effect on the virulence of the individual organisms (i.e. are the gram negative organisms in the vancomycin treatment group causing a higher reoperation rate than those in the untreated group?) (Table 5A-C). However, the virulence of each pathogen type appeared to be no different between the treated and untreated groups. These findings should be comforting to surgeons who use intraoperative vancomycin. That is, when SSI does develop in these patients, the outcomes are not adversely affected in terms reoperation rate, need for multiple antibiotics, and mean LOS. There are several potential limitations to this study. This was a retrospective study which employed existing documentation in the electronic medical record. In addition, this investigation was conducted at a single institution which serves as a referral center. As a result, the patients in the study may have more comorbidities and may have undergone more complex surgery than patients at other centers. As such, the microbial profile of our patients may not be generalizable. However, the aim of the study was to compare the microbial profile between the treatment and untreated arms, and there was no difference in comorbidities amongst these groups (Table 1). Another potential limitation is that there were not enough gram negative or polymicrobial SSIs to accurately perform multivariable logistic regression analysis to control for differences in patient characteristics (i.e. BMI, fusion procedure, history of previous surgery) amongst the two cohorts. Future studies with a larger sample size of gram negative and polymicrobial cultures are warranted for further investigation. Further investigation is also needed to determine whether the 24% of patients that were culture negative represented cases that were not actually SSIs versus SSIs with undetectable culture growth. Conclusion This study demonstrates an association between the use of vancomycin powder and a relative increase in prevalence of gram negative and polymicrobial organisms in patients ultimately developing SSI following thoracolumbar spine surgery However, this did not adversely affect the type of care required by the SSI patients, such as the need for multiple reoperations, complexity of antibiotic regimen, or length of stay in this series. Continued investigation is needed to evaluate whether the addition of local prophylactic antibiotics with gram negative coverage coupled with intraoperative vancomycin powder may further affect this microbial profile and serve as a safe and cost-effective means of further reducing the SSI rate in spine surgery.

References 1. Beiner JM , Grauer J , Kwon BK , et al. Postoperative wound infections of the spine . Neurosurg Focus. 2003; 15 : E14 .

2. Pull ter Gunne AF, Cohen DB: Incidence, prevalence, and analysis of risk factors for surgical site infection following adult spinal surgery. Spine (Phila Pa 1976). 2009;34:1422–1428. 3. Smith JS, Shaffrey CI, Sansur CA, Berven SH, Fu KM,Broadstone PA, et al: Rates of infection after spine surgery based on 108,419 procedures: a report from the Scoliosis Research Society Morbidity and Mortality Committee. Spine (Phila Pa 1976). 2011;36:556–563.

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4. Godil SS , Parker SL , O’Neill KR , et al. Comparative effectiveness and cost-benefi t analysis of local application of vancomycin powder in posterior spinal fusion for spine trauma . J Neurosurg Spine. 2013;19 : 331 – 5.

5. Sweet FA, Roh M, Sliva C: Intrawound application of vancomycin for prophylaxis in instrumented thoracolumbar fusions: efficacy, drug levels, and patient outcomes. Spine (Phila Pa 1976). 2011; 36:2084–2088. 6. Molinari RW, Khera OA, Molinari WJ III: Prophylactic intraoperative powdered vancomycin and postoperative deep spinal wound infection: 1,512 consecutive surgical cases over a 6-year period. Eur Spine J 21 (Suppl 4). 2012;S476–S482. 7. O’Neill KR, Smith JG, Abtahi AM, Archer KR, Spengler DM, McGirt MJ, et al: Reduced surgical site infections in patients undergoing posterior spinal stabilization of traumatic injuries using vancomycin powder. Spine J. 2011;11:641–646. 8. Strom RG, Pacione D, Kalhorn SP, Frempong-Boadu AK: Decreased risk of wound infection after posterior cervical fusion with routine local application of vancomycin powder. Spine (Phila Pa 1976). 2013;38:991–994. 9. Chiang HY, Herwaldt LA, Blevins AE, Cho E, Schweizer ML: Effectiveness of local vancomycin powder to decrease surgical site infections: a meta-analysis. Spine J. 2014 14:397–407. 10. Heller A, McIff TE, Lai SM, Burton DC: Intrawound vancomycin powder decreases staphylococcal surgical site infections after posterior instrumented spinal arthrodesis. J Spinal Disord Tech. 2015;28:E584–E589. 11. Dennis HH, Wei DT, Darren KZ, Shantakumar JT, Kumar N, Lau LL, et al: Is intraoperative local vancomycin powder the answer to surgical site infections in spine surgery? Spine (Phila Pa 1976).2016; [Epub ahead of print].

12. Adogwa O, Elsamadicy AA, Sergesketter A, et al. Prophylactic use of intraoperative vancomycin powder and postoperative infection: an analysis of microbiological patterns in 1200 consecutive surgical cases. J Neurosurg Spine. 2017;27(3):328-34.

13. Ghobrial GM, Thakkar V, Andrews E, et al. Intraoperative vancomycin use in spinal surgery: single institution experience and microbial trends. Spine (Phila Pa 1976). 2014;39(7):550-5.

14. Abdul-Jabbar A, Berven SH, Hu SS, Chou D, Mummaneni PV, Takemoto S, et al: Surgical site infections in spine surgery: identification of microbiologic and surgical characteristics in 239 cases. Spine (Phila Pa 1976).2013;38:E1425–E1431.

15. Khan NR, Thompson CJ, DeCuypere M, Angotti JM, Kalobwe E, Muhlbauer MS, et al: A meta-analysis of spinal. surgical site infection and vancomycin powder. J Neurosurg Spine. 2014;21:974–983.

16 Glassman SD, Dimar JR, Puno RM, Johnson JR: Salvage of instrumental lumbar fusions complicated by surgical wound infection. Spine (Phila Pa 1976). 1996; 21:2163–2169.

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Greg Kurkis, MD PGY-3 Emory University, Atlanta, GA July 2015 - Present Orthopaedic Surgery Resident Physician

University of Virginia School of Medicine, Charlottesville, VA May 2015 Doctor of Medicine, Alpha Omega Alpha Honor Society Spring 2014 Washington and Lee University, Lexington, VA May 2011 B.S. in Biochemistry, Summa Cum Laude, Phi Beta Kappa PUBLICATIONS, PRESENTATIONS & POSTERS Brent L. Finley, George N. Guild, Dennis J. Paustenbach, Rachel Novick, Andrew D.

Monnot, Ellen Donovan, Kenneth M. Unice, Ernest S. Fung, David Fung, Gregory M. Kurkis, and Michael Kovochich. Understanding Outcomes and Toxicological Aspects of Second Generation Metal-on-Metal Hip Implants: A State of the Art Review. Submitted and Accepted for Future Publication in Journal of Toxicology, Fall 2018

Gregory Kurkis, Albert Anastasio, Marijke Devos, Michael Gottschalk. Ultrasound-guided Aspiration Does Not Reduce the Recurrence Rate of Ganglion Cysts of the Wrist. Submitted for Publication to Journal of Wrist Surgery, April 2018.

Tyrrell Burrus M, Werner BC, Starman JS, Kurkis GM, Pierre JM, Diduch DR, Hart JM. Patient Perceptions and Current Trends in Internet Use by Orthopedic Outpatients. HSS J. 2017 Oct;13(3):271-275.

Burrus MT, Cancienne JM, Kurkis GM, et al. Equivalent Outcomes for Patients Following Trochleoplasty as a Primary or Revision Patellar Stabilizing Procedure. Orthopaedic Journal of Sports Medicine. 2017;5(7 suppl6).

Diduch DR, Burrus MT, Cancienne JM, Kurkis GM, Carstensen SE, Griffin JW, Werner BC. Trochleoplasty is a Viable Option for Patellar Instability in Patients with Severe Trochlear Dysplasia: Early Outcomes Analysis of the U.S. Experience. Orthopaedic Journal of Sports Medicine. 2017;5(7 suppl6).

Gregory Kurkis, Marijke Devos, Jordan Teboda, Michael Gottschalk. Ultrasound-guided Aspiration Does Not Reduce the Recurrence Rate of Ganglion Cysts of the Wrist. Poster Presentation. 2017 American Orthopaedic Association Annual Leadership Meeting. June 20-24, 2017, Charlotte, NC.

Gregory Kurkis (presenter), Marijke Devos, Jordan Teboda, Michael Gottschalk. Ultrasound-guided Aspiration Does Not Reduce the Recurrence Rate of Ganglion Cysts of the Wrist. Podium Presentation. 2017 Southern Orthopaedic Association Annual Meeting. June 28 – July 1, 2017, Hilton Head, SC.

Gregory Kurkis (presenter), Marijke Devos, Jordan Teboda, Michael Gottschalk. Ultrasound-guided Aspiration Does Not Reduce the Recurrence Rate of Ganglion Cysts of the Wrist. Podium Presentation. 2017 AAOS Annual Meeting. March 14-18, 2017, San Diego, CA. Burrus MT, Werner BC, Starman JS, Kurkis GM (presenter), Pierre JM, Diduch DR, Hart JM. Patient Perceptions and Current Trends in Internet Use by Orthopaedic Outpatients. Podium Presentation. 2017 AAOS Annual Meeting. March 14-18, 2017, San Diego, CA. Burrus MT, Cancienne JM, Kurkis GM, Carstensen SE, Griffin JW, Diduch DR. Trochleoplasty is a Viable Option for Patellar Instability in Patients with Severe Trochlear Dysplasia: Early Outcomes Analysis of the US Experience. Podium Presentation. 2017 AAOS Annual Meeting. March 14-18, 2017, San Diego, CA.

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Burrus MT, Kurkis GM, Conte EJ, Griffin JW, Werner BC, Hart JM, Diduch DR. Equivalent Outcomes for Patients Following Trochleoplasty as a Primary or Revision Patellar Stabilizing Procedure. Poster Presentation. 2017 AAOS Annual Meeting. March 14-18, 2017, San Diego, CA. Richard L Thomas, Gregory Kurkis. Chapter 1 - Compartment Syndrome and Necrotizing Fasciitis: Diagnosis. Book Chapter In: Kenneth J Koval, Paul Tornetta, eds. Let’s Discuss: Common Orthopaedic Emergencies – Surviving the Night. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2016. Werner BC, Kurkis GM, Gwathmey FW, Browne JA. Bariatric Surgery Prior to Total Knee Arthroplasty is Associated With Fewer Postoperative Complications. J Arthroplasty. 2015 Sept; 30 (9 Suppl): 81-5. Werner BC (presenter), Kurkis GM, Gwathmey FW, Browne JA. Bariatric Surgery Prior to Total Knee Arthroplasty is Associated with Fewer Postoperative Complications. Podium Presentation. 2015 AAOS Annual Meeting. March 24-28, 2015, Las Vegas, NV. Werner BC, Kurkis GM, Gwathmey FW, Browne JA (presenter). Does Bariatric Surgery Reduce Postoperative Complications Following Total Knee Arthroplasty? Podium Presentation. AAHKS Annual Meeting. November 6-9, 2014, Dallas, TX. Kurkis G, Tyger R - Video authors/contributors to “Anterior Cervical Decompression and Fusion” Chapter in: Shen F, Samartzis D, Fessler R, eds. Textbook of the Cervical Spine. 1st ed. Elsevier; Nov 2014. Mark D. Miller, Gregory Kurkis, Joseph Hart. “Anatomic ACL Reconstruction – All Comers.” American Academy of Orthopaedic Surgeons (AAOS) 2013 Annual Meeting – Presentation in Orthopaedic Video Theater and AAOS Resource Center Theater. Chicago, IL. March 20-22, 2013. Surgical Videos Produced with Dr. Mark Miller and Published to Orthobullets.com, Summer 2012: - “ACL Reconstruction with Hamstring Autograft” - “ACL Reconstruction with Patellar Tendon Autograft” - “Arthroscopic Biceps Tenodesis” - “Arthroscopic Meniscus Repair with All-Inside Technique” - “Arthroscopic Rotator Cuff Repair” - “Femoral Physeal Sparing ACL Reconstruction” - “MPFL Reconstruction with Free Soft Tissue Graft” - “Multiple Knee Ligament Injury Repair” - “Open Subpectoral Biceps Tenodesis” - “Revision ACL Reconstruction with Hamstring Autograft” - “Fulkerson Osteotomy”

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Ultra Sound Guided Aspiration Of Wrist Ganglion Cysts Does Not Reduce Recurrence Gregory Kurkis MD, Albert Anastasio BS, Marijke DeVos MD, Michael Gottschalk MD INTRODUCTION Ganglion cysts are a common upper extremity pathology encountered by hand surgeons. In fact, they are the most frequent soft tissue tumor encountered in the upper extremity, with the wrist being the most common location (1). Ganglion cysts of the wrist may arise from either an inflamed tendon sheath or from a degenerative and arthritic underlying joint. 60-70% occur on the dorsal aspect of the wrist, most commonly in the scapholunate region. Approximately 20% of wrist ganglions are volar, most commonly found between the flexor carpi radialis tendon and the first extensor compartment (2). Controversy remains as to the most effective treatment for this pathology. Observation, percutaneous aspiration, and open versus arthroscopic surgical excision are all options. Open surgical excision has a significantly lower chance of recurrence compared to aspiration, with a recurrence rate of 21% versus 59% shown in a recent systematic review and meta-analysis (3). However, surgical excision of wrist ganglions may be associated with an increased risk of complications such as wound infection or damage to surrounding anatomical structures. Also, surgical excision likely carries a more prolonged postoperative recovery and an increased cost of care. Despite the inferior recurrence rate, given the ease of performing in-office aspiration of a wrist ganglion and the potential complications and increased morbidity associated with surgical excision, aspiration still remains a valid treatment option. Ultrasound is becoming a widely used modality within orthopedics both for its role in assisting and improving bedside procedures as well as for its diagnostic utility. There is relatively little literature examining the role of ultrasound-guided aspiration of wrist ganglions. Zeidenberg et al. published a study in the radiology literature on a series of 39 patients at 9-month minimum follow up that had been treated with ultrasound-guided aspiration. They found a 20% recurrence rate in this group (4). Ultrasound provides the benefit of localizing the needle tip with visual confirmation within a ganglion prior to aspiration. Additional benefits might include minimizing the risk of damage to surrounding soft tissues and neighboring anatomical structures (5,6). At the time of our literature review, no studies were found comparing ultrasound-guided versus blind aspiration of wrist ganglion cysts. We hypothesize that ultrasound-guided aspiration will lead to improved recurrence rates and better patient outcomes compared to blind aspiration of ganglion cysts of the wrist. MATERIALS AND METHODS A chart review was conducted of all ganglion cysts of the wrist joint treated at our institution over 6 years (2009-2015). 186 patients were identified from this chart review. Of these 186 subjects, 114 patients were treated with attempted aspiration of the ganglion cyst; 27 of these 114 individuals underwent ultrasound-guided aspiration. Phone calls were placed to all 114 patients who had undergone attempted aspiration of their wrist ganglion cyst. Of these 114 patients, 52 could be reached by telephone and agreed to participate in the study. The information collected from these phone calls included confirmation of prior aspiration, other treatment history, obtaining up-to-date ganglion presence (e.g. recurrence status), any additional treatments undergone, and patient-reported Quick-DASH scores of upper extremity function from the afflicted wrist. Among those 52 patients who were successfully contacted by telephone, recurrence rates were compared between those whose cyst was treated with ultrasound-guided (13 patients) versus blind aspiration (39 patients). Additionally, patient reported Quick-DASH scores were compared between patients who experienced a recurrence after aspiration versus those who did not suffer a recurrence.

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Statistical analysis was performed using JMP Pro 12 (Cary, North Carolina). For continuous variables a T-test analysis was used to obtain p-values. For categorical or dichotomous variables, contingency tables were created and three analyses were carried out: Fisher exact test, a Z-score test for two population proportions, and N-1 Chi-squared testing. There was no difference in statistical significance for any variables among these three tests. Given the relatively small sample sizes involved with this study, Fisher exact test was utilized and reported. RESULTS Recurrence rates were 69% (9 patients) and 74% (29 patients) for the ultrasound-guided and blind aspiration groups respectively (p-value 0.73), showing no significant difference in recurrences of wrist ganglion between the two groups. The average follow-up time was 2.9 years to the time of phone follow-up from the time of aspiration. The average age at time of aspiration was 40 years for the ‘blind’ group versus 44 years for the ultrasound group. The ‘blind’ group was 74% female and the ultrasound group was 85% female, with only two male patients in the ultrasound-guided aspiration group. The ‘blind’ group was 47% African American and 42% Caucasian whereas the ultrasound-guided group was 75% Caucasian and 25% African American. In the ‘blind’ aspiration group, 74% of the cysts were dorsal and 18% were located on the volar aspect of the wrist; comparatively, in the ultrasound-guided aspiration group, 54% of the cysts were located dorsally versus 39% volarly. Steroid was injected at the time of aspiration in 82% of the ‘blind’ aspiration group and in all (100%) of the patients who received ultrasound-guided aspiration. 39% of the cysts in the ultrasound group were fenestrated with a needle at the time of aspiration compared 18% fenestration in the ‘blind’ aspiration group. Quick-DASH scores in the ‘blind’ aspiration group were higher (14.3) compared to the ultrasound-guided group (10.1). Of the above variables, none showed a statistically significant difference between the two groups, with all calculated p-values greater than 0.05. The average time to phone follow up from initial aspiration for the ‘blind’ aspiration group was 2.7 years versus 3.5 years for the ultrasound-guided aspiration group. For the recurrences encountered in the ultrasound group, the average reported time to recurrence after aspiration was 275 days, compared to 226 days to recurrence for the ‘blind’ aspiration group. Neither of these time variables were statistically significantly different between the two groups. Table 1. Recurrence Rates and Demographic Data for ‘Blind’ and Ultrasound-Guided Aspiration Groups

Ultrasound-Guided Aspiration ‘Blind’ Aspiration P-value Ganglion recurrence rate 69% 74% 0.73 Avg Age (years) 44 40 0.39 % Female 85% 74% 0.71 % African American 25% 47% 0.31 % Caucasian 75% 42% 0.09 % Volar Location 39% 18% 0.15 % Steroid Injected 100% 82% 0.17 % Fenestrated by Needle 39% 18% 0.15 Avg Quick-DASH Score 10.1 14.3 0.49 Avg Follow-up (yrs) 3.5 2.7 0.26

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Additionally, for those patients that experienced a ganglion recurrence after aspiration (either ‘blind’ or ultrasound-guided) Quick-DASH scores at the time of phone follow-up were greater (17.4) compared to the Quick-DASH scores of those patients that did not experience a recurrence (2.11); this was a statistically significant difference (p-value 0.008). DISCUSSION This study shows worse functional outcomes (higher Quick-DASH scores) in patients who experience a recurrence of wrist ganglion cysts after initial attempted aspiration. Thus, it is important to attempt to improve the efficacy of our aspiration techniques in an effort to improve patient outcomes and satisfaction. However, this research demonstrates no significant improvement in recurrence rates with the use of ultrasound-guided aspiration of ganglion cysts of the wrist. The intuitive benefits of using ultrasound to guide aspiration attempts are numerous, notably visual confirmation of accurate needle placement to ensure optimal and sufficient aspiration of the ganglion cyst. Additional benefits include minimization of damage to surrounding soft tissues and neighboring anatomical structures as well as potentially fewer needle sticks leading to decreased procedural-related discomfort for the patient. These benefits, combined with the relatively low risk of harm that comes with the addition of the use of ultrasound make for a compelling argument in the use of the management of ganglion cyst aspiration. Despite the results of this study showing no improvement in recurrence rates with the use of ultrasound guidance, there may be particular situations where use of ultrasound guidance for aspiration is warranted. Volar ganglion cysts as well as ganglion cysts that are in the vicinity of neurovascular structures may certainly benefit from the use of ultrasound-guided aspiration to ensure avoidance of damage to surrounding nerves, vessels, and soft tissues. For clinical settings that already have an ultrasound available on-site, there is little down-side in using ultrasound to guide aspiration attempts. Additionally, it should also be considered that use of ultrasound-guidance for needle placement may constitute an additional billable procedure for physicians in certain practice settings. Despite a thorough review of the literature, we found no prior studies comparing ultrasound-guided versus blind aspiration of ganglion cysts. The 69% recurrence rate with ultrasound-guided aspiration that we found in our analysis is higher than that seen in other studies. Zeidenberg et al. showed, in a series of 39 patients followed for 9 months, a 20% recurrence rate with ultrasound-guided aspiration (4). Although this recurrence rate is significantly less than that demonstrated in our study, the average follow-up time was 15 months, shorter than the 42-month mean follow up time in our group. Breidahl and Adler conducted a case series of 10 patients that underwent ultrasound-guided treatment of ganglion cysts (6). 7 of these were located at the wrist. Of those 7 ganglia, 2 resolved completely, 1 recurred 1 year after attempted aspiration, 3 experienced a reduction in size of the ganglion with improved symptoms but persistence of the cyst, and 1 patient did not experience any noticeable relief. Other research on blind aspiration of wrist ganglion cysts showed a wide range with similar high recurrence rates as those seen in our data. The recurrence rates reported in the literature for blind aspiration of wrist ganglions range from 27% to 89% (7,8). Regardless of aspiration technique and the use of ultrasound, recurrence rates of ganglion cysts of the wrist are high, as demonstrated both in our study as well as throughout the literature. This should be discussed with patients, and they should be counseled on the risks, benefits, and likelihood of success of aspiration versus excision. While a less-invasive option is always a preferred initial treatment, given the overall poor efficacy of aspiration, proceeding straight to surgical excision may provide patients with a more reliable solution with a quicker return to symptom-free function. Limitations of this study include its small sample size and relatively low rate of successful phone follow-up. This study would benefit from addition of more study participants to increase sample sizes and improve power. Additionally, given the retrospective design of our study and the lack of randomization of subjects to blind or ultrasound-guided aspiration groups, there could have been additional factors not identified in our study that led the treating physician to pursue ultrasound-guided versus blind aspiration based on certain patient

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presentations, cyst locations, or other factors. Future studies should look toward a randomized, prospective controlled trial to further investigate the possible benefit of ultrasound-guided aspiration of ganglion cysts of the wrist. Additionally, this study could be expanded to investigate the role of ultrasound in the management of ganglion cysts in other anatomical locations beyond the wrist. More research would also be useful in assessing any morbidity associated with ultrasound-guided aspiration. Although, it can be assumed that procedure-related morbidity and complications would likely be less with aspiration in comparison to open resection, it would be useful to investigate if ultrasound-guidance led to an improvement in treatment-associated morbidity compared to morbidity and complications associated with blind aspiration. REFERENCES 1. Operative Techniques in Orthopedic Surgery, 2nd Ed. Eds Gerald Williams, Matthew Ramsey, Brent Weisel. Vol 3. Open and Arthroscopic Excision of Ganglion Cysts and Related Tumors. Mitchell Nahra John Bucchieri. Ch. 110: 3529-3560. 2. Angelides AC. Ganglions of the hand and wrist. In Green DP, Hotchkiss RN, Pederson WC eds. Operative Hand Surgery, vol 2, ed 5. New York: Churchill Livingstone, 1999: 2171-2183.

3. Linden Head, John Robert Gencarelli, Murray Allen, Kirsty Usher Boyd. Wrist Ganglion Treatment: Systematic Review and Meta-Analysis. J Hand Surg Am. Vol 40 March 2015. 546-553.

4. Zeidenberg J, Aronowitz JG, Landy DC, Owens PW, Jose J. Ultrasound-guided aspiration of wrist ganglions: a follow up survey of patient satisfaction and outcomes. Acta Radiologica. 2015; 0 (e-pub): 1-6.

5. The J, Vlychou M. Ultrasound-guided interventional procedures of the wrist and hand. European Radiology. 2009; 19:1002-10.

6. Breidahl W, Adler R. Ultrasound-guided injection of ganglia with corticosteroids. Skeletal Radiology. 1996; 25: 635-38.

7. Teh J, Vlychou M. Ultrasound-guided interventional procedures of the wrist and hand. European Radiology. 2009; 19:1002-10.

8. Louis L. Musculoskeletal ultrasound intervention: principles and advances. Radiol Clin N Am. 2008; 46: 515-33.

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Nick N. Patel, MD PGY-3 Emory University, Atlanta, GA July 2015 - Present Orthopaedic Surgery Resident Physician Emory University School of Medicine, May 2015 Doctor of Medicine Georgia Institute of Technology Aug 2009 – May 2011 B.S. in Biomedical Engineering, Graduated with Highest Honors Dual Degree Program with Emory Emory University Aug 2006 – May 2009 B.S. in Biology, Dual Degree Program with Georgia Tech

PATENTS “Access Device for Surgery” – Co-inventor Patent number US8771173 B2 Issued July 8, 2014 • A surgical device that provides minimally invasive access for sterile endoscopes to organs including the beating heart • Can stabilize the heart, create a working space, provide direct visualization, and deliver therapies such as stem cells • Other applications include delivery of therapeutics, transmyocardial revascularization, ablation, echo-probe diagnostics, LAA isolation and procedural observation PUBLICATIONS, PRESENTATIONS & POSTERS Fletcher ND, Lazarus DE, Desai MJ, Patel NN, Bruce RW. Medicaid insurance is associated with larger curves in patients who require scoliosis surgery. Am J Orthop. 2015 Nov;44(11):E454-7.

Wise BT, Patel NN, Wier G, Labib SA. Outcomes of ACL Reconstruction With Fixed Versus Variable Loop Button Fixation. Orthopedics. 2017 Mar 1;40(2):e275-e280.

Patel NN, Labib SA. The Achilles Tendon in Healthy Subjects: An Anthropometric and Ultrasound Mapping Study. J Foot Ankle Surg. 2018 Mar - Apr;57(2):285-288.

Patel NN, Guild GN, Erens GA. Femoral Head-Trunnion Dissociation in Metal-on-Polyethylene Total Hip Arthroplasty – A Unique Case Report. Reconstructive Review. 2017 Dec;7(4).

Patel NN, Bruce RW. Transcapsular Buttonholing of the Proximal Ulna as a Cause for Irreducible Pediatric Anterior Elbow Dislocation: A Case Report. Accepted for publication Apr 2018 in Case Reports in Orthopedics.

Gottschalk MB, Patel NN, Boden AL, Kakar S. Treatment of Basilar Thumb Arthritis: A Critical Analysis Review. Accepted for publication Jan 2018 in JBJS.

PRESENTATIONS The Achilles Tendon in Healthy Subjects: An Anthropometric and Ultrasound Mapping Study New Orleans, LA Eastern Orthopedic Association: Podium Presentation Oct 20, 2016

Outcomes of ACL Reconstruction With Fixed Versus Variable Loop Button Fixation Amelia Island, FL Eastern Orthopedic Association: Podium Presentation Oct 22, 2014 Outcomes of ACL Reconstruction With Fixed Versus Variable Loop Button Fixation Atlanta, GA Annual Emory Research Symposium Apr 23, 2015

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CURRENT PROJECTS Emory University School of Medicine, Department of Orthopaedics Atlanta, GA The Use of Intra-wound Vancomycin Powder in Hip and Knee Arthroplasty PI: Dr. George Guild Performing a retrospective review of >500 surgical patients to analyze the potential benefits of routine intra-wound vancomycin powder in arthroplasty surgery. Surgeon Preferences and Perceptions Regarding the Direct Anterior Approach for Hip Arthroplasty PI: Dr. Greg Erens Currently in the process of surveying fellowship trained arthroplasty surgeons regarding their perceptions and preferences towards DAA for hip arthroplasty. We aim to gain insight into factors driving surgical choice as well as those providing barriers to transitioning surgical practice. Treatment of Infection Through Thermal Heating of Implants Currently combining my passions for orthopedics and engineering in order to investigate the ability of in-vivo electromagnetic heating to clear infection from implanted hardware. My goal is to develop a way to eradicate biofilm on implants and, therefore reduce the need for revision surgery to remove infected hardware. Comparison of Early Outcomes of Total Elbow Arthroplasty Based on Surgical Indication Performing an analysis of the NSQIP Database in order to identify difference in early outcomes for TEA based on surgical indication

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Intra-wound Vancomycin in Primary Hip & Knee Arthroplasty – A Safe and Cost Effective Means to Decrease Prosthetic Joint Infection Nick N. Patel, MD; George N. Guild III, MD; Arun Kumar, MD Introduction

The utilization of hip and knee arthroplasty has been steadily increasing due to an active aging population. It is projected that the number of total hip and knee replacements will approach greater than 570,000 and 3.4 million respectively by 2030 [1]. Despite substantial research and robust multimodal programs to mitigate infection, periprosthetic joint infection (PJI) continues to be a devastating complication to patients and the health care system. PJI rates have continued to average between 0.5-2% [2-4], and it is estimated that by 2020, $1.62 billion will be spent on revisions for infection in the U.S. alone [5].

Many PJI prevention strategies have been developed ranging from preoperative screening, intraoperative methods, and postoperative intervention with varying levels of success. One such prevention strategy has been the use of intraoperative vancomycin powder. Although this has been well described in the spine surgery literature including its safety and effectiveness [6, 7], information regarding the use of intra-wound vancomycin in the arthroplasty setting is almost nil.

Several studies do exist supporting the use of intra-wound antibiotics for total joint arthroplasty in animal models. Separate in-vivo rat investigations performed by Edelstein et al. and Cavanaugh et al. both demonstrated the effectiveness of intra-wound antibiotics on clearing staph aureus from contaminated femoral implants [8, 9]. Johnson et al. recently published data supporting the safety of vancomycin powder placed intra-articular after arthroplasty [10]. While there is basic science and spine literature supporting the use of intra-wound vancomycin powder, there is a paucity of clinical data in its efficacy for prevention of PJI.

The most common pathogen in infected total joint arthroplasty is staphylococcal species[11], and an increasing incidence of methicillin resistant Staphylococcus aureus (MRSA) has made vancomycin a reasonable choice for intra-wound antibiotics[12]. Potential benefits of intra-wound antibiotics include maximizing local bactericidal concentrations while minimizing adverse systemic effects. Despite these potential benefits, there are numerous questions regarding this practice including safety information on seroma formation, bearing wear, nephrotoxicity and ototoxcitiy. Further questions exist to whether this practice truly decreases infection rates.

The objective of this study is to determine if the routine use of intra-wound vancomycin powder resulted in a decreased periprosthetic joint infection rate as the primary outcome metric in our large volume, academic, teaching hospital. Secondary outcomes include safety metrics based on 90 day all cause readmissions, mechanical complications, nephrotoxicity, ototoxicity, and cost data.

Materials and Methods

This retrospective investigation was performed in accordance with our institutional review board. Operative records for patients having undergone primary total hip or knee arthroplasty from April 2016 through October 2017 were analyzed for a single fellowship trained arthroplasty surgeon. This timeline was selected to use contemporary data with an updated PJI prevention program rather than historical data which may introduce confounding variables. Furthermore, one year of clinical practice, October 2016 to October of 2017, was chosen as the experimental consecutive cohort with intra-wound vancomycin to be able to report all infection and complications that may occur over a year of clinical practice. 112 consecutive surgeries without

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vancomycin powder were used as the control consecutive cohort, followed by 348 consecutive surgeries used as the experimental intra-wound vancomycin group. All surgeries were performed at the same institution which is a large volume, urban, academic-teaching hospital. Inclusion criteria included patients undergoing primary total hip or knee arthroplasty with indication of osteoarthritis, osteonecrosis, post-traumatic arthritis, as well as inflammatory arthropathies. Patients were excluded if they were undergoing a revision surgery. With this criteria, no patient undergoing a primary total hip or knee replacement was excluded from either group for any reason over the above mentioned time period, minimizing potential for sampling bias and aiding in its generalizability to other populations. Standard patient pre-operative screening measures included BMI<40, Hemoglobin A1C<7, appropriate dentition, smoking cessation, nasal MRSA screening, and optimization of medical comorbidities such as renal failure, COPD, CHF, and anticoagulation.

Preoperatively, patients received dosed intravenous cephalosporin within one hour prior to incision; however, intravenous vancomycin was administered instead for those with a history of anaphylaxis to penicillins. Hoods and cloth gowns were utilized during surgery. After hardware implantation, a three-minute dilute betadine soak of the surgical wound was performed followed by irrigation using one liter of normal saline with 50,000 units of bacitracin on all patients. Starting in October 2016, the principle surgeon routinely applied one gram of vancomycin powder into the surgical wound prior to closure in primary hip and knee arthroplasties. The antibiotic powder was applied into the joint and surrounding muscle, fascia and subcutaneous tissues. No antibiotics were placed in bone cement in any hip or knee. Subcutaneous vicryl suture followed by subcuticular monocryl and dermabond was routinely utilized for hip closure, and staples with occlusive dressing (Aquacel Ag, ConvaTec, Bridgewater, NJ) were used for knee replacement.

Our institution participates in the Center for Disease Control and Prevention’s National Healthcare Safety Network (NHSN) for surveillance and reporting of deep and superficial surgical site infections (SSI)[13]. A review of this database located all patients who had been identified as having an SSI within the designated timeline. Additionally, operative records for all patients of the primary surgeon were reviewed to ensure that all infections were in fact captured. Subjects were grouped based on whether they did receive intra-wound vancomycin (October 2016 – October 2017) or did not (April 2016 – September 2016). Information regarding patient demographics, baseline characteristics, comorbidities and operative data was collected. Culture positive superficial wound infections and deep joint infection (subfascial intra-articular) were included. Superficial wound infections were routinely treated with irrigation, debridement, and closure, followed by a course of antibiotics, while deep infections were treated with one or two stage revision procedures depending on chronicity. Minor postoperative wound complications such as stitch abscesses or erythema that were treated with routine postoperative wound care were not considered wound infections and thus not included in the infection data. Return to the OR for hematoma or seroma that met Musculoskeletal Infection Society (MSIS) criteria for infection, or simply had a single positive culture were included in the infection data. In addition, post-operative sub-metrics including 90-day all-cause readmission, acute kidney injury (AKI) and ototoxicity were recorded. AKI was considered an increase of > 0.3mg/dL in serum creatinine post-operatively. Student t-test was utilized to compare numerical variables while Fischer exact test was used to compare categorical variables.

Results

From April 2016 through October 2017, a total of 460 primary total hip and knee arthroplasty cases were performed by the primary surgeon that satisfied inclusion and exclusion criteria (217 TKA, 243 THA) (Table 1). Patients were similar in terms of demographics, comorbidities and other operative variables for those with and without vancomycin (Table 2). The control primary arthroplasty group had an overall infection rate of 2.7%, which included 3 deep infections and 0 superficial infections. The vancomycin powder cohort had and overall infection rate of 0.57%, which included 1 superficial and 1 deep infection (Table 3). The deep infection rate in the vancomycin group was 0.29%. The decrease in overall infection rate from 2.7% to 0.57% (p = 0.031) and deep infection rate from 2.7% to 0.29 (p=0.009 ) with the addition of vancomycin powder were both statistically significant. There was no significant difference in incidence of post-operative AKI or ototoxicity. The control

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group had a 5.4% 90-day all-cause hospital readmission rate while the vancomycin group had a rate of 3.2% (p = 0.14). When analyzing various factors for readmission, there was no statistical difference in readmission rate for non-infectious wound issues, mechanical complications, or medical issues unrelated to the index procedure (p > 0.05, Table 4). As expected, the control group had a statistically higher 90-day readmission rate due to infection compared to the vancomycin subset (2.7% vs. 0.57%, p = 0.031). Table 5 demonstrates detailed information regarding the cases of infections in both subsets including bacteria cultured, time to repeat surgery, risk factors, and clinical outcome. One TKA patient in the control group had multiple recurrences of infection and required an eventual above knee amputation. The remaining four infections cleared clinically after surgical intervention.

Table 1

Table 2

Table 3

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Table 4

Table 5

Discussion

The use of intra-wound vancomycin powder has been well described in the spine surgery literature

with regards to safety and efficacy in reducing surgical site infection[6, 7, 14]. With regard to total joints, Otte

et al. demonstrated a reduced infection rate for hip and knee arthroplasty with the addition of vancomycin

powder but only in the revision setting[15]. Dial et al. recently showed a decreased infection rate in a series of

primary hip arthroplasties but did find an increased incidence of associated sterile seroma[16]. Results of our

investigation demonstrate a significantly decreased overall infection rate from 2.7% to 0.57% for primary total

hip and knee arthroplasty with the addition of intra-wound vancomycin. More notably, the most significant

reduction observed was in deep PJI with an infection rate of 0.29% (p = 0.009).

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The PJI rate for control primary cases in our series was found to be 2.7% which is slightly higher than

the reported 0.5%- 2.0% described in the literature [2-4]. This increased infection rate is thought to be partly

attributable to the patient population seen at our institution which is a high volume tertiary referral center.

Patients in our cohort had an average BMI > 30, 11.3% rate of active smokers, and 10.4% rate of diabetes

mellitus, all of which are known PJI risk factors after arthroplasty surgery [17-19]. Additionally, patients of lower

socioeconomic status have been shown to have a higher incidence of PJI, and our institution is one of the sole

providers for Medicaid patients in the area[20]. Although smoking cessation as a standard practice was

implemented during the study period, subsequently a negative urine nicotine has been required at pre-

anesthesia testing. The increased infection rate in the control group was the impetus to evaluate a new strategy

to prevent PJI: intra-wound vancomycin powder.

Concerns have been raised regarding the safety of intra-wound vancomycin. Studies have

demonstrated low morbidity associated with intra-wound vancomycin in surgical spine cases [21]. Similarly, an

investigation by Johnson et al. attested to the safety of 2g of intra-articular vancomycin powder in arthroplasty

surgery[10]. They found highly therapeutic vancomycin concentrations in the local tissue yet low systemic

levels. Our results are in agreement with the previous published data on safety, as there was no significant

difference in post-operative acute kidney injury or ototoxicity between the control and vancomycin groups.

There was a low threshold in this study to include AKI as a complication with increase in creatinine of 0.3 mg/dl.

The one patient in the vancomycin group who experienced AKI had a correction of creatinine to baseline after

24 hours of fluid hydration with no long-term nephrotoxic sequelae. There was also no statistical significant

difference in seroma formation in the vancomycin group. There was one seroma in the vancomycin group that

required an irrigation and debridement in the postoperative period who had five negative cultures and was not

treated with antibiotics. That patient did heal uneventfully and no further surgical intervention was required.

The authors suggest that this work contributes to the existing literature on safety regarding the use of intra-

wound vancomycin powder.

The efficacy of intra-wound vancomycin powder has been debated in the spine literature. Strom et al.

showed that the implementation of intra-wound vancomycin powder is particularly beneficial in decreasing

infection rates in posterior cervical fusion surgery when current high rates exist[22]. In their study, the infection

rate decreased from 10% to 2.5%. Other studies from the spine literature show that if the existing infection

rate is low, then the routine use of vancomycin powder is of little benefit [23]. The authors of this manuscript

cannot comment on what infection rate should trigger a root cause analysis in total joint arthroplasty, but just

a general guideline that if the exiting infection rate is >2% [4] then an investigation with tracked solutions

should be performed locally. This is the scenario that prompted the investigation and potential solution to the

increased infection rate at the authors’ institution (2.7%). Since the single change to protocol in October of

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2016, only one patient had a deep infection in that year with an infection rate of 0.29%. The single infection

occurred in a patient with rheumatoid arthritis who unknowingly used recreational amphetamines which may

have contributed to his delayed wound healing and subsequent deep infection. Despite routine drug use, the

patient was included in the study in an effort to be generalizable to other surgeon’s practices and for full

transparency. The authors attribute the lower infection rate in this study to the use of intra-wound vancomycin,

as other confounders such as surgeon technique, implants, facility, and multimodal PJI prevention strategies

were identical between groups. The authors have continued to routinely use intra-wound vancomycin powder

on all primary and revision total joint arthroplasties.

The introduction of a crystalline substance into a prosthetic joint provokes thought about

premature third-body implant wear; however, Qadir et al. demonstrated no appreciable implant wear with the

addition of intra-articular vancomycin in a biomechanical study [24]. High concentrations of certain antibiotics

have been shown to be cytotoxic towards osteoblasts[25]. Vancomycin exhibited one of the weakest effects

on osteoblast growth and osteogenic activity, thus making it suitable for local delivery[25, 26]. This concept is

particularly important in the arthroplasty setting with regards to implant fixation and bony ongrowth. With the

follow-up period in our investigation, we did not note any issues with aseptic loosening; however, this could

be more appreciable with long-term data. Furthermore, long-term information about the osteogenic effects of

intra-wound vancomycin may provide insight into potential differences in outcomes between cemented or

cementless implants.

The vast financial burden on patients and healthcare system associated with PJI imparts particular

importance when discussing the economics with intra-wound vancomycin. At our institution, one gram of

vancomycin powder costs $17, which is on par with the rates at other facilities[27]. The addition of intra-wound

vancomycin in this investigation led to a decrease in the overall infection rate from 2.7% to 0.57% suggesting

an absolute risk reduction (ARR) of 2.13% or 0.21. This leads to the determination of number needed to treat

(NNT) as 47.5 (NNT = 1/ARR). In other words, 48 primary total hip or knee arthroplasties need to be performed

with the addition of vancomycin powder to prevent one case of prosthetic joint infection. At the rate of $17

per patient, the total cost with the addition of intra-wound vancomycin to prevent one PJI is $816. This is a

relatively insignificant cost in comparison to an estimate of the 2018 average hospital cost per case of infected

THA ($30,329) and TKA ($25,155)[28].

The strengths of the study are that it is a single surgeon series, at one institution, without change in

infection prevention protocols over the study period. This potentially limited confounding variables which can

be numerous in an infection study. The potential for sampling bias was limited by the fact that no patient was

eliminated from either group unless it was a revision surgery. The consecutive nature of the surgeries

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performed in each group may afford some protection from selection bias; however, the non-randomized

nature of the study is a limitation. Other limitations include the low effect size with regards to number of

surgical site infections. A sample size of 3,416 patients would be required to adequately detect a 50% reduction

in infection rate from 2.7% to 1.35% with power of 0.80 and alpha 0.05. To obtain this number of control group

patients, a historical control infection rate would have to be utilized, or information used from more than one

surgeon which would introduce other confounding variables and protocol changes. Furthermore, several

consecutive years of clinical practice would be required to identify enough vancomycin group patients to gain

appropriate power which would delay the reporting of a potentially safe and beneficial strategy in decreasing

PJI. Consideration was given to including data from other surgeons and institutions but the authors believe

this would have introduced numerous confounding variables in an effort to increase sample size. Future

research on increasing the sample size to allow for appropriate power without introducing confounders is a

worthy endeavor. The allotted sample size of 460 was however, sufficient in detecting the significantly

decreased infection rate noted in this investigation.

The authors suggest that the use of intra-wound vancomycin is safe in short term follow and was

protective in preventing early postoperative complications or readmissions. Its usage shows promise in

reducing the incidence of PJI, particularly if an increased rate of PJI is present or the hospital population is at

risk. Furthermore, intra-wound vancomycin is a low-cost option with a low number needed to treat to show

value. Future research aimed at adding sample size without the introduction of confounding variables is

necessary before any formal recommendations for its routine use in total joint arthroplasty can be made.

References

1. Kurtz, S., et al., Projections of primary and revision hip and knee arthroplasty in the United States from

2005 to 2030. J Bone Joint Surg Am, 2007. 89(4): p. 780-5. 2. Kurtz, S.M., et al., Infection burden for hip and knee arthroplasty in the United States. J Arthroplasty,

2008. 23(7): p. 984-91. 3. Namba, R.S., M.C. Inacio, and E.W. Paxton, Risk factors associated with deep surgical site infections

after primary total knee arthroplasty: an analysis of 56,216 knees. J Bone Joint Surg Am, 2013. 95(9): p. 775-82.

4. Urquhart, D.M., et al., Incidence and risk factors for deep surgical site infection after primary total hip arthroplasty: a systematic review. J Arthroplasty, 2010. 25(8): p. 1216-22 e1-3.

5. Haddad, F.S., A. Ngu, and J.J. Negus, Prosthetic Joint Infections and Cost Analysis? Adv Exp Med Biol, 2017. 971: p. 93-100.

6. Bakhsheshian, J., et al., The use of vancomycin powder in modern spine surgery: systematic review and meta-analysis of the clinical evidence. World Neurosurg, 2015. 83(5): p. 816-23.

7. Hey, H.W., et al., Is Intraoperative Local Vancomycin Powder the Answer to Surgical Site Infections in Spine Surgery? Spine (Phila Pa 1976), 2017. 42(4): p. 267-274.

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8. Cavanaugh, D.L., et al., Better prophylaxis against surgical site infection with local as well as systemic antibiotics. An in vivo study. J Bone Joint Surg Am, 2009. 91(8): p. 1907-12.

9. Edelstein, A.I., et al., Intra-Articular Vancomycin Powder Eliminates Methicillin-Resistant S. aureus in a Rat Model of a Contaminated Intra-Articular Implant. J Bone Joint Surg Am, 2017. 99(3): p. 232-238.

10. Johnson, J.D., et al., Serum and Wound Vancomycin Levels After Intrawound Administration in Primary Total Joint Arthroplasty. J Arthroplasty, 2017. 32(3): p. 924-928.

11. Tyllianakis, M.E., et al., Antibiotic prophylaxis in primary hip and knee arthroplasty: comparison between cefuroxime and two specific antistaphylococcal agents. J Arthroplasty, 2010. 25(7): p. 1078-82.

12. Chen, L.F., C. Chastain, and D.J. Anderson, Community-Acquired Methicillin-Resistant Staphylococcus aureus Skin and Soft Tissue Infections: Management and Prevention. Curr Infect Dis Rep, 2011. 13(5): p. 442-50.

13. CDC, Surgical Site Infection (SSI) Event. 2017. 14. Thompson, G.H., et al., Does Vancomycin Powder Decrease Surgical Site Infections in Growing Spine

Surgery?: A Preliminary Study. J Bone Joint Surg Am, 2018. 100(6): p. 466-471. 15. Otte, J.E., et al., Intrawound Vancomycin Powder Reduces Early Prosthetic Joint Infections in Revision

Hip and Knee Arthroplasty. Surg Technol Int, 2017. 30: p. 284-289. 16. Dial, B.L., et al., Intrawound Vancomycin Powder in Primary Total Hip Arthroplasty Increases Rate of

Sterile Wound Complications. Hip Pelvis, 2018. 30(1): p. 37-44. 17. Gonzalez, A.I., et al., Is There an Association Between Smoking Status and Prosthetic Joint Infection

After Primary Total Joint Arthroplasty? J Arthroplasty, 2018. 18. Triantafyllopoulos, G.K., et al., Rate and Risk Factors for Periprosthetic Joint Infection Among 36,494

Primary Total Hip Arthroplasties. J Arthroplasty, 2018. 33(4): p. 1166-1170. 19. Iorio, R., et al., Diabetes mellitus, hemoglobin A1C, and the incidence of total joint arthroplasty

infection. J Arthroplasty, 2012. 27(5): p. 726-9 e1. 20. Webb, B.G., D.M. Lichtman, and R.A. Wagner, Risk factors in total joint arthroplasty: comparison of

infection rates in patients with different socioeconomic backgrounds. Orthopedics, 2008. 31(5): p. 445. 21. Ghobrial, G.M., et al., Complications from the use of intrawound vancomycin in lumbar spinal surgery:

a systematic review. Neurosurg Focus, 2015. 39(4): p. E11. 22. Strom, R.G., et al., Decreased risk of wound infection after posterior cervical fusion with routine local

application of vancomycin powder. Spine (Phila Pa 1976), 2013. 38(12): p. 991-4. 23. Tubaki, V.R., S. Rajasekaran, and A.P. Shetty, Effects of using intravenous antibiotic only versus local

intrawound vancomycin antibiotic powder application in addition to intravenous antibiotics on postoperative infection in spine surgery in 907 patients. Spine (Phila Pa 1976), 2013. 38(25): p. 2149-55.

24. Qadir, R., et al., Establishing a role for vancomycin powder application for prosthetic joint infection prevention-results of a wear simulation study. J Arthroplasty, 2014. 29(7): p. 1449-56.

25. Rathbone, C.R., et al., Effect of various concentrations of antibiotics on osteogenic cell viability and activity. J Orthop Res, 2011. 29(7): p. 1070-4.

26. Mendoza, M.C., et al., The effect of vancomycin powder on bone healing in a rat spinal rhBMP-2 model. J Neurosurg Spine, 2016. 25(2): p. 147-53.

27. Hatch, M.D., et al., The cost effectiveness of vancomycin for preventing infections after shoulder arthroplasty: a break-even analysis. J Shoulder Elbow Surg, 2017. 26(3): p. 472-477.

28. Kurtz, S.M., et al., Economic burden of periprosthetic joint infection in the United States. J Arthroplasty, 2012. 27(8 Suppl): p. 61-5 e1.

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Dale Segal, MD PGY-3 Emory University, Atlanta, GA July 2015 - Present Orthopaedic Surgery Resident Physician Herbert Wertheim College of Medicine, May 2015 Doctor of Medicine University at Albany, State University of New York May 2010 B.S. in Biochemistry & Molecular Biology PEER REVIEWED JOURNAL PUBLICATIONS Segal DN, Wilson JM, Staley C, ST Yoon. Outpatient and Inpatient Single-Level Cervical Total Disc Replacement: A Comparison of 30-day Outcomes. Accepted to Spine May 2018

Segal DN, Wilson JM, Staley C, Michael KW. The 5-item Modified Frailty Index is Predictive of 30-day Postoperative Complications in Patients Undergoing Kyphoplasty Vertebral Augmentation. World Neurosurgery 2018; doi.10.1016 Segal DN, Grabel ZJ, Shi JW, Gottschalk MB, Boden SD, National Access to Spine Care, Accepted to Orthop. Rev. May 2018 Iobst C, Arango D, Segal D, Skaggs DL. National access to care for children with fractures J Pediatric Orthopedics. 2013; 33:587-91 Segal DN, Grabel ZJ, Wilson JM, Shi JW, Milby AM, Hutton PW, Rhee JM. Total Disc Replacement Adjacent to a Multilevel Fusion. Submitted to Clinical Spine Journal: under review Grabel ZJ, Boden A, Segal DN, Milby AH, Heller JG The Impact of Prophylactic Intraoperative Vancomycin Powder on Microbial Profile, Antibiotic Regimen, Length of Stay, and Reoperation Rate in Elective Spine Surgery. The Spine Journal: Revisions under Review Shi JW, Garrard E, Segal DN, Grabel ZJ, Schell A, Rhee JM. Increased adjacent segment motion after ACDF: How is it distributed in the cervical spine? Manuscript submitted to Global Spine: Under review National Presentations Segal DN, Grabel ZJ, Wilson JM, Shi JW, Milby AM, Hutton PW, Rhee JM. Total Disc Replacement Adjacent to a Multilevel Fusion: A Biomechanical Motion Analysis. North American Spine Society. 33rd NASS Annual Meeting, Los Angeles, CA Sept. 2018 Segal DN, Wilson JM, Staley C, Michael KW. The 5-item Modified Frailty Index is Predictive of 30-day Postoperative Complications in Patients Undergoing Kyphoplasty Vertebral Augmentation. North American Spine Society 33rd NASS Annual Meeting, Los Angeles, CA Sept. 2018 Iobst C, Arango D, Segal D, Skaggs DL. National Access to Care for Children with Fractures. American Academy Orthopedic Surgery AAOS Annual Meeting March 2013 Chicago, IL International Presentations Grabel ZJ, Boden A, Segal DN, Milby AH, Heller JG The Impact of Prophylactic Intraoperative Vancomycin Powder on Microbial Profile, Antibiotic Regimen, Length of Stay, and Reoperation Rate in Elective Spine Surgery. Scoliosis Research Society SRS 53rd Annual Meeting Bologna, Italy Oct. 2018 West J, Segal D, Gonzalez-Arias S. Sympathetic Denervation Supersensitivity in the Eye Results in Increased Alpha-1 Adrenergic Receptor Expression. WFNS 2013. 15th Congress of the World Federation of Neurosurgical Societies. 2013 Sep 8-13; Seoul, Korea. West J, Segal D, Segui D, Gonzalez-Arias S. Application of Minimally Invasive Surgical Techniques to Treatment of Lumbar Synovial Cysts. WFNS 2013. 15th Congress of the World Federation of Neurosurgical Societies. 2013 Sep 8-13; Seoul, Korea.

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Regional Presentations Segal DN, Grabel ZJ, Wilson JM, Shi JW, Milby AM, Hutton PW, Rhee JM. Total Disc Replacement Adjacent to a Multilevel Fusion: A Biomechanical Motion Analysis. Southern Orthopedic Association West Palm Beach, FL. July. 2018 Winner of the Harley & Better Baxter Award Segal DN, Grabel ZJ, Shi JW, Gottschalk MB, Boden SD, National Access to Spine Care, Eastern Orthopedics Annual Meeting Oct. 2017 Miami, FL

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Total Disc Replacement Adjacent to a Multilevel Fusion in the Cervical Spine: A Biomechanical Study Dale N. Segal, MD, Zachary J. Grabel, MD, Jacob M. Wilson, MD, Andrew H. Milby, MD, Weilong J Shi,MD, William C. Hutton, DSc, John M. Rhee, MD

Abstract

Background Context: The cervical total disc replacement (TDR) has emerged as a motion-preserving alternative to anterior cervical discectomy fusion (ACDF). Biomechanical studies have demonstrated that the TDR preserves motion at the diseased segment and minimizes motion and stress at adjacent segments compared to fusion. There has been growing interest in performing a TDR adjacent to a cervical fusion.

Purpose: The purpose of this study was to investigate the kinematics of a TDR after sequentially fusing adjacent segments.

Methods: Seven fresh-frozen human cadaveric cervical spine specimens from C1-T1 were used (average age 56.2 ± 7.3 years). The effect on cervical flexion-extension motion, by instrumenting a TDR above or below a one, two or three-level fusion, was measured. The protocol consisted of taking fluoroscopic images of each cervical specimen obtained at maximal angular displacement in flexion and extension during force application. Cobb angles were measured on the digital radiographs to determine flexion- extension range of motion.

Results: The segmental range of motion (ROM) of the C6-7 TDR in the unfused spine was 11.3 ±1.9°. After performing a three-level fusion at C3-6, the motion of the C6-7 TDR increased to 12.9

±1.3°(p=0.33). The ROM of the C2-3 TDR in the unfused spine was 5.0 ±1.1°. After performing a three- level fusion of C3-6, the C2-3 TDR segmental motion was 6.1 ±1.3° (p=0.09).

Conclusion: Biomechanically performing a cervical total disc replacement adjacent to a long segment fusion did not subject the implant to significantly greater motion than when the TDR was instrumented alone.

Introduction

Anterior cervical discectomy and fusion (ACDF) is a well-established procedure with favorable outcomes and high levels of patient satisfaction(1, 2). Despite its widespread utilization, adjacent segment disease after ACDF remains a clinical concern. Prior studies have demonstrated that spine mechanics are altered at segments adjacent to fusion, potentially leading to hypermobility and accelerated degenerative changes(3-7). Biomechanical studies have demonstrated that a cervical total disc replacement (TDR) may preserve motion at the diseased segment while minimizing motion and stress at adjacent segments(8-10). Cervical TDR has emerged as an alternative to ACDF with favorable outcomes(10-13). In addition, cervical TDR has shown promise as a potential option for treatment of degeneration adjacent to prior ACDF constructs. The kinematics of the cervical spine with a TDR adjacent to a long fusion construct (>2 levels) has not been documented.

Early clinical results of a cervical disc replacement adjacent to a single level ACDF are encouraging(12-14). In a biomechanical study, Lee et al(15) demonstrated cervical disc replacement adjacent to a single level fusion improves overall spine motion and reduces compensatory adjacent segment spine motion

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compared with a two-level cervical fusion. A similar cadaveric study revealed cervical replacement adjacent to a two-level fusion is not associated with hypermobility at the level of the disc replacement(16). The purpose of this study was to measure the segmental cervical spine motion of a TDR adjacent to a long fusion construct (>2 levels). In this investigation we evaluated the flexion-extension segmental motion of the cervical spine with a TDR adjacent to a single, two and three level fusion. We also compared the implant motion to a control native disc with adjacent fusions at corresponding levels. We hypothesized that there would be no significant increase in the degree of flexion-extension motion in the TDR instrumented alone or adjacent to a one, two or three level fusion.

Materials and Methods

Materials

Seven fresh-frozen human cadaveric cervical spine specimens from C1-T1 were used (5 men, 2 women; average age 56.2 ± 7.3 years). The seven specimens were selected after screening in order to exclude any with prior cervical surgery, metastatic disease, auto-fusion, or congenital anomalies. The specimens were thawed at room temperature for 24 hours prior to the experimental protocol. Paravertebral muscles were dissected taking care to preserve osseous, ligamentous and disc material. Fluoroscopy was employed to confirm appropriate levels. Three screws were inserted radially into the body of T1 to aid in cement fixation and the specimens were potted in dental cement up to the caudal endplate of C7.

An external fixator construct was applied to each of the seven cadaver specimens for the purpose of simulating a fusion construct in a non-destructive fashion. The construct was composed of 3 mm diameter Schanz pins inserted from anterior to posterior into the bodies of C3-C6 with care not to damage the adjacent soft tissue structures. Carbon fiber rods were used to rigidly fix each Schanz pin to the adjacent pins using pin-to-bar clamps, thus allowing for simulation of fusion at different spinal segments within the same specimen.

Experimental Procedure

A 4.0-mm diameter threaded screw was inserted from cephalad to caudad into the body of C2. A tensioning cable was secured to this screw. The cable was used to apply a flexion force or an extension force to the cervical spine. The force in each case was applied in a direction parallel to the cephalad endplate of C2 as described by Horton et al(17). We applied a constant 40 N. A force of this magnitude achieved maximal angular displacement (in flexion and in extension) and allowed the spine to return to its neutral position within its elastic region, as defined during pilot studies. Each specimen was preconditioned by subjecting it to 5 cycles of flexion-extension at 40N prior to testing. The protocol consisted of fluoroscopic images of the specimen obtained at maximal angular displacement in flexion during force application (Figure 1). The procedure was then repeated with the specimen at maximal angular displacement in extension during force application.

Two experiments were performed on each cervical specimen:

Experiment 1: We tested spine motion when a TDR was instrumented below a multilevel fusion by placing the implant at C6-7 in the C2-7 specimen (Figure 2). After completing experiment 1, the TDR at C6-7 was removed and the specimen was potted up to the C6 caudal endplate. We then moved to experiment 2.

Experiment 2: We tested the spine motion when a TDR was instrumented above a multilevel fusion by inserting the implant at C2-3 (figure 2). The C2-6 cervical spine was used for this experiment.

The stepwise protocol for each experiment is described below.

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Disc replacement below fusion: Experiment 1

Step1: Lateral fluoroscopic images were obtained for the native cervical spine at flexion and extension end points under the 40 N force described above.

Step 2: A single level fusion was simulated at C5-6 using the pin-bar construct described and fluoroscopic images were obtained at both flexion and extension end points.

Step 3-4: This process was repeated for a two-level fusion of C4-6 and a three-level fusion of C3-6.

Step 5: Next, the fusion construct was disassembled and a C6-7 discectomy was performed. A NuVasive PCM cervical disc was inserted into the C6-7 disc space as described in the technique guide (NuVasive, Inc. 7475 Lusk Blvd., San Diego, CA 92121 USA). The prosthesis was appropriately sized so as to not over tension the stabilizing soft tissue structures. Placement was confirmed under image intensification.

Step 6: With the prosthetic disc in place, the cervical spine was again tested in flexion and extension and fluoroscopic images were obtained.

Step 7-9: With the C6-7 TDR adjacent to a one-level fusion (C5-6) a two-level fusion (C4-6) and a three-level fusion (C3-6); the cervical spine was again tested in flexion and extension and fluoroscopic images were obtained.

Step 10: The fusion construct was removed and the cervical spine was tested in flexion and extension and fluoroscopic images were obtained. The purpose of this step was to confirm that baseline motion, as observed in step 1, was preserved.

The above 10-step protocol was carried out for all seven specimens.

Disc replacement above fusion: Experiment 2

After completion of experiment 1, the implant was removed from the C6-7 disc space and the specimen was re-potted in dental cement up to the C6 inferior endplate. Thus, a C2-6 specimen was used for this portion of the experiment.

Step 1: First, lateral fluoroscopic images were obtained for the native cervical spine at the flexion end point and then at the extension end point under the 40 N force described above.

Step 2: A single level fusion was simulated at C3-4 using the pin bar construct and radiographs were taken at both flexion and extension end points.

Step3-4: This process was repeated for a two-level fusion of C3-5 and a three-level fusion of C3- 6

Step 5: Next, the rod-to-rod connectors were removed and a C2-3 discectomy was performed. A NuVasive PCM cervical disc was inserted into the C2-3 disc space as described above.

Step 6: With the prosthetic disc in place, the cervical spine was again tested in flexion and extension and lateral fluoroscopic images were obtained.

Step 7-9: This process was repeated with the C2-3 TDR adjacent to a one-level fusion (C3-4), a two-level fusion (C3-5) and a three-level fusion (C3-6); the cervical spine was tested in flexion and extension and fluoroscopic images were obtained after each step.

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Step 10: The fusion construct was removed and the cervical spine was again tested in flexion and extension and fluoroscopic images were obtained. The purpose of this step was to confirm that baseline motion was preserved as measured in step 1.

The above 10-step protocol was carried out for all seven specimens.

After the biomechanical testing was complete, the digital fluoroscopic images were analyzed on the PACS system (GE Centricity PACS Radiology 1000 workstation). The C2-7 Cobb angles were measured in flexion and in extension as described by Park et al(18) to quantify the overall range of motion (ROM). The segmental motion was assessed by measuring the flexion and extension Cobb angles of C2-3, C3-4, C4-5, C5-6 and C6-7. Cobb angles were measured three times to determine intra-observer agreement. Three independent blinded observers repeated the measurements in order to determine inter-observer reliability. The ROM was obtained by summation of the flexion and extension values. The average flexion-extension ROM values for the seven specimens at each segment were used for the final analysis.

Data Analysis:

In order to validate the fusion model, the segmental ROM in the native cervical spine was compared to that in the fused spine. To demonstrate the integrity of the spine after removal of the external fixator fusion construct, we compared the segmental motion of the specimen prior to external fixator placement to the segmental motion after external fixator removal. C2-3 and C6- 7 were not considered in this comparison as the prosthetic disc had been placed in these segments.

We compared the segmental motion at the level of the TDR implant when instrumented as a stand-alone device and when placed adjacent to a one, two and three level fusion. These comparisons were made for both the TDR above and below a multi-level fusion. We also compared the segmental motion of the TDR to that of the native disc at the corresponding level. These comparisons were made for the unfused specimen, and for the one, two and three level fusions above and below the TDR. We assessed the overall motion of the cervical specimen instrumented with a stand-alone TDR implant and compared it to the overall motion of the control native specimen. Finally, we compared the overall cervical motion with the TDR adjacent to a one, two and three level fusion construct to that of the control spine with corresponding levels fused.

Repeated-measures analyses were used to analyze segmental motion using a means model via the SAS MIXED Procedure (version 9.4; SAS Institute, Cary, NC), providing separate estimates of the means by TDR group, fusion level and cervical location. A compound-symmetric variance-covariance form in repeated measurements was assumed for each outcome, and robust estimates of the standard errors of parameters were used to perform statistical tests and construct 95% confidence intervals(19). Predictors included in each model were TDR group, fusion level, cervical location and the interaction between TDR group, fusion level and cervical location. All specific statistical tests were done within the framework of the mixed effects linear model, using t tests to compare differences between the model-based means. The results were summarized with model-based means and 95% confidence intervals by TDR group, fusion level and cervical location. Statistical tests were two-sided and unadjusted for multiple comparisons. A p value < .05 was considered statistically significant.

Results

Effect of Simulated Fusion

As expected, the external fixator fusion construct reduced flexion-extension motion. We measured the segmental ROM on the flexion-extension radiographs of the C2-7 cadaver specimen and compared it

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to the segmental motion after performing the C3-6 fusion. The C3-6 ROM in flexion-extension was reduced from 29.3 5.3 in the native spine to 2.9 2.1 after a C3-6 fusion (p<0.0001) (Table 1).

Reversibility of Fusion Construct

Removal of the fusion construct allowed the spine to return to its native state. This was demonstrated by comparing the total flexion-extension ROM of the native spine at C3-6 prior to fusion to the motion at C3-6 after fusion construct was removed; 29.3 5.3 versus 35.3 4.9, respectively(p=0.11).

Motion with a C6-7 TDR below a three-level fusion in the C2-7 cervical spine

The segmental ROM of the C6-7 TDR in the unfused spine was 11.3 1.9. After performing a three-level fusion (C3-6) the segmental motion of the C6-7 TDR increased to 12.9 1.3. This difference was not statistically significant (p=0.33) (Table 1). In the native spine, the flexion- extension ROM at C6-7 of the native segment was 9.2 2;whereas, the ROM of C6-7 after performing a C3-6 fusion was 11.3 1.9 (p=0.18). The difference between the motion of the C6-7 TDR segment below a three-level fusion (12.9 1.3) and the C6-7 native disc below a three-level fusion (11.3 1.9) was not statistically significant (p=0.30)(Figure 3). The overall C2-7 motion in the native specimen compared to specimen with a C6-7 TDR was 39.3 ± 5.4° versus 42.1 ± 7.6°, respectively (p=0.38). After performing a C3-6 fusion, the C2-7 overall motion between the specimen with the native C6-7 segment and the one with a C6-7 TDR were similar; 24.3 ± 5.6° versus 27.3 ± 5.1° (p=0.27) (Figure 4).

Motion of a TDR at C2-3 above a three-level fusion in the C2-6 cervical spine

The segmental ROM of the C2-3 TDR in the unfused spine was 5.0 1.1. After performing a three-level fusion (C3-6), the C2-3 TDR segmental motion was 6.1 1.3. This difference was not statistically significant (p=0.09) (table 2). In the native spine, there was a significant difference in the flexion and extension ROM at the C2-3 native segment (4.4 0.9°) compared with the ROM after performing a C3-6 fusion (6.4 0.8) (p=0.001). The difference in motion of the TDR above a three-level fusion and the native disc above a three-level fusion was not statistically significant; 6.1 ± 1.3 versus 6.4 ± 0.8, respectively (p=0.15) (figure 5). The overall C2-6 motion in the native specimen compared to specimen with a C2-3 TDR was 32.1 ± 5.9° versus 32.8 ± 4.8°, respectively (p=0.77). After performing a C3-6 fusion the C2-6 overall motion between the specimen with the native C2-3 segment and the one with a C2-3 TDR were similar; 10.3 ± 1.9° versus 9.3 ± 1.3° (p=0.33) (Figure 6).

Inter-observer reliability

The overall inter-observer agreement was 0.91. The intra-observer agreement was 0.95.

Discussion

The primary result demonstrated by this study is that there was no significant difference in cervical TDR motion when instrumented alone or adjacent to a one, two or three level fusion. Furthermore, there was no significant difference in segmental motion at the level of the TDR implant compared to the corresponding native segment when instrumented above or below a fusion construct. This held true irrespective of its placement adjacent to a one, two or three-level fusion. In our study there was a small trend towards increased motion in the TDR as the number of levels fused adjacent to this segment increased however the magnitude of the observed difference was small and therefore unlikely to be clinically relevant.

Our results are consistent with previous kinematic studies. Lee et al. concluded that the motion of the PCM cervical total disc replacement adjacent to a fused level is comparable with that of a stand-alone prosthesis(15). Their study did not find a significant difference in the motion of the prosthesis when

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the fused level was below or above to the TDR. Martin et al assessed motion of a C3-4 disc arthroplasty implanted as a standalone and above a 2 level fusion and found that there was no increase in compensatory motion when subjected to a constant load(16).

There are several limitations to this study. First, this investigation did not employ a compressive load on the cervical spine to simulate the force of the head, known as the follower load technique, but rather used pure bending moments(15, 16, 20, 21). Theoretically, pure bending moments are more likely to subject the spine to shearing forces which may lead to structural damage. Additionally, we used a load control rather than a displacement control method for applying the flexion and extension force to the spine; displacement control poses an increased risk of damaging the specimens through overload. Despite using pure bending moments and a load control method, the specimens in our study remained intact, which was demonstrated by verifying segmental motion after testing was complete. No assessment of rotational motion was performed. Our experimental protocol did not include destructive testing of specimens. As such, we extrapolated from individual trials performed within the elastic region of the flexion- extension arc to assess whether a segment may experience additional range of motion within physiologic activity, as this may contribute to accelerated adjacent segment degeneration. No

conclusions can be drawn regarding the propensity of TDR adjacent to long fusion toward prosthesis loosening or catastrophic failure with supra-physiologic loading. Cobb angles from lateral fluoroscopic imaging were used to measure flexion-extension angles. These measurements demonstrated satisfactory intra-observer predictability and inter-observer reliability scores. Our fusion model did not completely eliminate segmental motion which may have been due to the biomechanical nature of the construct or Cobb-angle measurement error. These values were consistent with previous studies and are unlikely to be clinically significant. Our study failed to reject the null hypothesis which could have been due to our sample size of seven specimens and the study being underpowered. However, a post-hoc power analysis demonstrated that four specimens would have been sufficient to find a 10° difference in segmental motion (a value that we would have considered clinically significant). Lastly, the implant utilized for the study (Nuvasive PCM) is not FDA approved for instrumentation at C2-3. The purpose of utilizing this level was to maximize adjacent caudal fusion segments in order to illustrate its effect on motion.

In conclusion, in this biomechanical experiment we observed no significant difference in cervical TDR motion when instrumented alone, or above or below, a one, two or three-level fusion.

Furthermore, there was no significant difference in segmental motion at the level of the TDR implant compared to the corresponding native segment when instrumented above or below a one, two, or three-level fusion. These results suggest that performing a TDR adjacent to a long anterior cervical fusion preserves native flexion-extension at that level and is not subjected to excessive compensatory motion.

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TDR A djacent to M ultilevel Fusion Overall motion

C2-3 motion

C3-4 motion

C4-5 motion

C5-6 motion

C6-7 motion

Native (C2-7) 39.3°±5.4 (4.0)

4.3°±1.6 (1.3)

8.9°±1.6 (1.2)

9.9°±1.8 (1.4)

10.5°±3.6 (2.7)

9.2°±2.8 (2.0)

C5-6 Fusion 34.5°±6.4 (4.8)

5.4°±3.5 (2.6)

10.7°±1.4 (1.0)

10.3°±4.2 (3.1)

1.2°±0.7 (0.5)

10.2°±2.1 (1.6)

C4-6 Fusion 29.9°±10.2 (7.6)

5.5°±1.5 (1.1)

10.4°±2.9 (2.2)

1.4°±0.9 (0.7)

1.3°± 1.0 (0.8)

10.9°±2.7 (2.0)

C3-6 Fusion 24.3°±5.6 (4.1)

5.7°±1.8 (1.4)

1.3°±0.7 (0.5)

1.1°±0.6 (0.4)

1.1°±0.3 (0.2)

11.9°±2.2 (1.7)

C6-7 TDR 42.1°±7.6 (5.7)

5.3°±2.0 (1.5)

9.6°±1.7 (1.2)

10.4°±1.6 (1.3)

10.8°±2.6 (1.9)

11.3°±2.6 (1.9)

C5-6 Fusion/C6-7 TDR

39.3°±3.9 (2.9)

5.3°±1.0 (0.7)

10.7°±2.5 (1.9)

11.2°±3.3 (2.5)

1.0°±0.7 (.05)

11.7°±1.3 (1.0)

C4-6 Fusion/ C6-7 TDR

33.3°±4.4 (3.2)

5.9°±1.7 (1.3)

12.0°±1.7 (1.3)

1.5°±0.8 (0.6)

0.9°±0.5 (0.4)

13.6°±2.8 (2.1)

C3-6 Fusion/ C6-7 TDR

27.3°±5.1 (4.0)

5.9°±1.5 (1.1)

1.2°±0.5 (0.4)

1.9°±1.1 (0.8)

1.5°±1.0 (0.8)

12.2°±2.2 (1.7)

Table 1. Flexion Extension Motion of a TDR below a Fusion

Overall motion

C2-3 motion

C3-4 motion

C4-5 motion

C6-7 motion

Native(C2-6) 32.1°±5.9 (4.4)

4.4°±.0.9 (0.7)

9.2°±1.6 (1.2)

9.7°±1.4 (1.1)

9.9°±3.9 (2.9)

C3-4 Fusion 28.1°±4.9 (3.6)

5.1°±0.8 (0.6)

1.0°±0.7 (0.5)

10.9°±1.7 (1.3)

10.2°±3.1 (2.3)

C3-5 Fusion 22.0°±3.0 (2.2)

5.9°±1.0 (0.8)

0.9°±0.8 (0.6)

1.5°±0.7 (0.5)

11.0°±3.1 (2.3)

C3-6 Fusion 10.3°±1.9 (1.4)

6.4°±0.8 (0.6)

0.9°±0.5 (0.4)

1.11°±0.5 (0.4)

1.0°±0.6 (0.4)

C2-3 TDR 32.8°±4.8 (3.6)

5.0°±1.5 (1.1)

9.8°±1.3 (1.0)

10.6°±2.6 (2.0)

10.2°±2.8 (2.1)

C3-4 Fusion/ C2-3 TDR

28.1°±3.6 (2.7)

4.8°±1.6 (1.2)

1.0°±0.5 (0.4)

10.3°±2.2 (1.6)

9.3°±3.0 (2.2)

C3-5 Fusion/ C2-3 TDR

19.2°±3.2 (2.4)

4.8°±1.7 (1.2)

1.5°±0.5 (0.4)

1.1°±0.5 (0.4)

9.7°±4.3 (3.1)

C3-6 Fusion/ C2-3 TDR

9.3°±1.3 (1.0)

6.1°±1.3 (1.1)

1.2°±0.9 (0.7)

1.0°±0.5 (0.4)

1.2°±0.8 (0.6)

Table 2. Flexion Extension Motion of a TDR above a Fusion

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Figure 1.

Flexion(left) and extension(right) fluoroscopic images of a cervical total disc replacement instrumented at C6-7. Cobb angles were measured to determine the segmental range of motion.

Figure 2.

Examples of fluoroscopic images used to assess motion. a) C6-7 TDR with no fused segments b) C6-7 TDR adjacent to a simulated C5-6 fusion c) C2-3 TDR above a C3-5 simulated fusion and d) C2-3 TDR above a C3-6 simulated fusion.

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Figure 3. Motion of the C6-7 native segment and the C6-7 TDR below a multilevel fusion. Error bars represent 95% confidence interval.

Figure 4. Overall C2-7 cervical spine motion with a C6-7 TDR below a multilevel fusion compared to the native segment. Error bars represent 95% confidence interval.

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Figure 5.

Motion of the C2-3 native segment and the C2-3 TDR above a multilevel fusion. Error bars represent 95% confidence interval.

Figure 6.

Overall C2-6 cervical spine motion with a C2-3 TDR above a multilevel fusion compared to the native segment. Error bars represent 95% confidence interval.

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REFERENCES:

1. Hacker RJ. A randomized prospective study of an anterior cervical interbody fusion device with a minimum of 2 years of follow-up results. J Neurosurg. 2000;93(2 Suppl):222-6. 2. Goffin J, Geusens E, Vantomme N, Quintens E, Waerzeggers Y, Depreitere B, et al. Long-term follow-up after interbody fusion of the cervical spine. J Spinal Disord Tech. 2004;17(2):79-85. 3. Hilibrand AS, Carlson GD, Palumbo MA, Jones PK, Bohlman HH. Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis. J Bone Joint Surg Am. 1999;81(4):519-28. 4. Braunstein EM, Hunter LY, Bailey RW. Long term radiographic changes following anterior cervical fusion. Clin Radiol. 1980;31(2):201-3. 5. Eck JC, Humphreys SC, Lim TH, Jeong ST, Kim JG, Hodges SD, et al. Biomechanical study on the effect of cervical spine fusion on adjacent-level intradiscal pressure and segmental motion. Spine (Phila Pa 1976). 2002;27(22):2431-4. 6. Park DH, Ramakrishnan P, Cho TH, Lorenz E, Eck JC, Humphreys SC, et al. Effect of lower two-level anterior cervical fusion on the superior adjacent level. J Neurosurg Spine. 2007;7(3):336-40. 7. Schwab JS, Diangelo DJ, Foley KT. Motion compensation associated with single-level cervical fusion: where does the lost motion go? Spine (Phila Pa 1976). 2006;31(21):2439-48. 8. DiAngelo DJ, Roberston JT, Metcalf NH, McVay BJ, Davis RC. Biomechanical testing of an artificial cervical joint and an anterior cervical plate. J Spinal Disord Tech. 2003;16(4):314- 23. 9. DiAngelo DJ, Foley KT, Morrow BR, Schwab JS, Song J, German JW, et al. In vitro biomechanics of cervical disc arthroplasty with the ProDisc-C total disc implant. Neurosurg Focus. 2004;17(3):E7. 10. Pickett GE, Rouleau JP, Duggal N. Kinematic analysis of the cervical spine following implantation of an artificial cervical disc. Spine (Phila Pa 1976). 2005;30(17):1949-54. 11. Heller JG, Sasso RC, Papadopoulos SM, Anderson PA, Fessler RG, Hacker RJ, et al. Comparison of BRYAN cervical disc arthroplasty with anterior cervical decompression and fusion: clinical and radiographic results of a randomized, controlled, clinical trial. Spine (Phila Pa 1976). 2009;34(2):101-7. 12. Lee SB, Cho KS. Cervical arthroplasty versus anterior cervical fusion for symptomatic adjacent segment disease after anterior cervical fusion surgery: Review of treatment in 41 patients. Clin Neurol Neurosurg. 2017;162:59-66. 13. Phillips FM, Allen TR, Regan JJ, Albert TJ, Cappuccino A, Devine JG, et al. Cervical disc replacement in patients with and without previous adjacent level fusion surgery: a prospective study. Spine (Phila Pa 1976). 2009;34(6):556-65. 14. Rajakumar DV, Hari A, Krishna M, Konar S, Sharma A. Adjacent-level arthroplasty following cervical fusion. Neurosurg Focus. 2017;42(2):E5.

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15. Lee MJ, Dumonski M, Phillips FM, Voronov LI, Renner SM, Carandang G, et al. Disc replacement adjacent to cervical fusion: a biomechanical comparison of hybrid construct versus two-level fusion. Spine (Phila Pa 1976). 2011;36(23):1932-9. 16. Martin S, Ghanayem AJ, Tzermiadianos MN, Voronov LI, Havey RM, Renner SM, et al. Kinematics of cervical total disc replacement adjacent to a two-level, straight versus lordotic fusion. Spine (Phila Pa 1976). 2011;36(17):1359-66.

17. Horton WC, Kraiwattanapong C, Akamaru T, Minamide A, Park JS, Park MS, et al. The role of the sternum, costosternal articulations, intervertebral disc, and facets in thoracic sagittal plane biomechanics: a comparison of three different sequences of surgical release. Spine (Phila Pa 1976). 2005;30(18):2014-23. 18. Park MS, Moon SH, Lee HM, Kim TH, Oh JK, Nam JH, et al. Age-related changes in cervical sagittal range of motion and alignment. Global Spine J. 2014;4(3):151-6. 19. Diggle PJ LK, Zeger SL. Analysis of longitudinal data. In: Press C, editor. Analysis of longitudinal data. 2nd ed. Oxford1994. p. 68-9. 21. Patwardhan AG, Havey RM, Ghanayem AJ, Diener H, Meade KP, Dunlap B, et al. Load- carrying capacity of the human cervical spine in compression is increased under a follower load. Spine (Phila Pa 1976). 2000;25(12):1548-54.

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David Shau, MD, MBA PGY-3 EDUCATION

Emory University, Atlanta, GA July 2015 - Present Orthopaedic Surgery Resident Physician Vanderbilt University School of Medicine, May 2015 Doctor of Medicine Vanderbilt University Owen School of Business May 2015 Master of Business Administration University of Texas at Austin May 2010

HONORS AND AWARDS Eastern Orthopaedic Association Travel Grant: Eastern Orthopaedic Society • Awarded $1000 for abstract titled: Increased Resource Utilization in Medicaid Patients following Primary Hip Arthroplasty. This grant was given to a resident with one of the top abstracts accepted for presentation at EOA’s Annual Meeting. Invited to present at annual conference hosted in Miami, FL in October 2017.

Georgia Orthopaedic Society Paper Competition – 2nd Place: Georgia Orthopaedic Society • Second place and $1000 award for abstract titled: Increased Resource Utilization in Medicaid Patients following Primary Hip Arthroplasty. Invited to present at annual conference hosted in Cloister Island, GA in October 2017.

PUBLICATIONS Shau DN, Shenvi N, Easley K, Smith M, Guild G. Medicaid Payer Status is Associated with Increased 90-day Morbidity and Resource Utilization following Primary Total Knee Arthroplasty: a Propensity Score Matched Analysis. Submitted to JOA. [In progress] Shau DN, Shenvi N, Easley K, Smith M, Bradbury T, Guild G. Medicaid Payer Status is Associated with Increased 90-day Morbidity and Resource Utilization following Primary Total Hip Arthroplasty: a Propensity Score Matched Analysis. The Journal of Bone and Joint Surgery, Submitted July 2017. [Pending Review] Shau DN, Patton R, Patel S, Ward L, Guild G. Synthetic Mesh vs. Allograft Extensor Mechanism Reconstruction in Total Knee Arthroplasty – A Systematic Review of the Literature and Meta-Analysis. The Knee, January 2018. Shau DN, Traub B, Kadakia R, Labib S, Bariteau J. Health Policy – Ethics, Regulatory, and Financial Aspects of Innovation in Orthopaedics: Introducing New Orthopaedic Technology in the Current Healthcare Environment. Techniques in Orthopaedics, September 2017. Shau DN, Guild G. Book Title: Complex Cases in Total Knee Arthroplasty: A Compendium of Current Techniques. Chapter 9: Acute Infection, Two Stage Procedure with Mobile Spacer. Springer, September 2017. Armaghani SJ, Lee DS, Bible JE, Shau DN, Kay H, Zhang C, McGirt MJ, Devin CJ. Increased Preoperative Narcotic Use and Its Association With Postoperative Complications and Length of Hospital Stay in Patients Undergoing Spine Surgery. Clin Spine Surg, March 2016.

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Bible JE, Shau DN, Kay HF, Cheng JS, Aaronson OS, Devin CJ. Are Low Patient Satisfaction Scores always Due to the Provider? Determinants of Patient Satisfaction Scores During Spine Clinic Visits. Spine, January 2016. Kelly PD, Parker SL, Mendenhall SK, Bible JE, Sivasubramaniam P, Shau DN, McGirt MJ, Devin CJ. Cost-Effectiveness of Cell Saver in Short-Segment Lumbar Laminectomy and Fusion (≤3 Levels). Spine, April 2015. Bible JE, Kay HF, Shau DN, O'Neill KR, Segebarth PB, Devin CJ. What Patient Characteristics could Potentially affect Patient Satisfaction Scores during Spine Clinic? Spine, April 2015.

PRESENTATIONS

Shau DN, Smith M, Bradbury T, Guild G. Medicaid Payer Status is Associated with Increased 90-day Morbidity and Resource Utilization following Primary Total Hip Arthroplasty: a Propensity Score Matched Analysis. [Podium] AAOS, 2018. Guild G, Shau DN, Smith M. Medicaid Payer Status is Associated with Increased 90-day Morbidity and Resource Utilization following Primary Total Knee Arthroplasty: a Propensity Score Matched Analysis. [Podium] AAOS, 2018. Shau DN, Patton R, Patel S, Ward L, Guild G. Synthetic Mesh vs. Allograft Extensor Mechanism Reconstruction in Total Knee Arthroplasty – A Systematic Review of the Literature and Meta-Analysis. [Poster] AAHKS, 2017. Guild G, Shau DN, Smith M. Medicaid Payer Status is Associated with Increased 90-day Morbidity and Resource Utilization following Primary Total Knee Arthroplasty: a Propensity Score Matched Analysis. [Poster] AAHKS, 2017. Guild G, Shau DN, Smith M, Bradbury TL. Increased Resource Utilization in Medicaid Patients following Primary Hip Arthroplasty. [Podium] Eastern Orthopaedic Association, 2017. Guild G, Shau DN, Smith M, Bradbury TL. Increased Resource Utilization in Medicaid Patients following Primary Hip Arthroplasty. [Podium] Georgia Orthopaedic Society, 2017.

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Increased Resource Utilization in Medicaid Patients following Primary Total Hip Arthroplasty

Shau DN, Shenvi N, Easley K, Smith M, Bradbury T, Guild G.

ABSTRACT

Background:

Medicaid payer status has been shown to affect risk-adjusted outcomes and resource utilization

across multiple medical specialties. The purpose of this study is to examine resource utilization via

readmission rates, length-of-stay, and total cost specific to Medicaid payer status following primary total

hip arthroplasty (THA).

Methods:

The Nationwide Readmissions Database (NRD) was utilized to identify patients who underwent

THA in 2013 as well as corresponding “Medicaid” or “non-Medicaid” payer statuses. Demographics,

fourteen individual comorbidities, readmission rates, length-of-stay, and direct cost were evaluated. A

propensity-score-based matching model was utilized to control for baseline confounding variables

between payer groups. Following propensity-score matching, chi-square test was used to compare

readmission rates between the two payer groups. The relative risk (RR) with 95% confidence-intervals (CI)

was estimated to quantify readmission risk. Length-of-stay and total cost comparisons were evaluated

using the Wilcoxon signed rank test.

Results:

A total of 5,311 Medicaid and 144,814 non-Medicaid THA patients were identified from the 2013

NRD. A propensity score was estimated for each patient based on the available baseline demographics,

and 5,311 non-Medicaid patients were propensity-score matched to the 5,311 Medicaid patients.

Medicaid vs. non-Medicaid payer status yielded statistically significant differences in overall readmission

rates of 28.8% vs. 21.0% (p<0.001, RR=1.37, 95% CI [1.28-1.46]) and 90 day hip-specific readmission rates

of 2.5% vs. 1.8% (p=0.01, RR=1.38, 95% CI [1.07-1.78]). Mean length-of-stay was greater in Medicaid group

compared to non-Medicaid group at 4.5 days vs. 3.3 days (p<0.0001) as well as mean total cost of $71,110

vs. $65,309 (p<0.0001).

Conclusions:

This study demonstrates that Medicaid payer status is independently associated with increased

resource utilization, including readmission rates, length-of-stay, and total cost following primary THA.

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Providers may have a disincentive to treat patient populations who require increased resource utilization

following surgery. Risk adjustment models accounting for Medicaid payer status are necessary to avoid

decreased access to care for this patient population and to avoid financial penalty for physicians and

hospitals alike.

Level of Evidence:

Prognostic Level III.

INTRODUCTION

Over the last six decades, the Medicaid program has grown from a healthcare coverage program

for welfare recipients into a large public health insurance program for low income and disabled

Americans1. Medicaid now provides coverage for over 72 million patients and is the single largest health

insurance plan in the United States2. The Affordable Care Act expanded the Medicaid program by creating

a national Medicaid minimum eligibility level of 133% of the federal poverty level beginning in 2014, which

has been estimated to increase the number of individuals younger than 65 years of age by approximately

12 million3,4. Total hip arthroplasty is among the largest and fastest growing healthcare expenditures

accounting for nearly $3 billion in Medicare reimbursement in 2013 alone5,6. Recent healthcare reform

has tasked hospitals, surgeons, and policymakers to reduce cost while maintaining quality in total hip

arthroplasty. Medicare programs such as the Medicare Bundled Payment for Care Improvement Initiative

and the Comprehensive Care for Joint Replacement Model aim to align incentives to contain costs through

bundling payments for an episode of care from time of surgery through 90 days post discharge7-9. While

the early results of these alternative payment models (APM’s) seem promising10, concern remains

regarding patient selection and access to care11.

Medicaid insurance status and lower socioeconomic status have repeatedly been shown affect

risk-adjusted outcomes and resource utilization across multiple medical specialties12-14. Varying

explanations for this finding have described this disparity including complex interaction between

socioeconomic status, access to care, patient factors, and clinical outcomes measures. Data has been

limited to small retrospective studies that suggest Medicaid patients who undergo total joint arthroplasty

are more likely to have a longer length-of-stay, disposition to a rehabilitation facility, and increased

readmission within 90 days15, 16. Despite evidence that patients with Medicaid status require more

resources at increased cost, payers have yet to provide adjustment in reimbursement based on Medicaid

payer status. With the increasing prevalence of APM’s there may be a disincentive to perform THA’s on

patients with Medicaid status.

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The purpose of this study is to evaluate the 90 days post-operative readmission and resource

utilization associated with Medicaid payer status following THA. A large, national administrative database

was utilized to achieve a comprehensive analysis and allow Medicaid patients to be matched one-to-one

with control patients who differed only in payer status. This publication uniquely examines Medicaid payer

status as an independent risk factor for morbidity and increased resource utilization on a national level

and is the largest patient sample to date. The primary hypothesis is that Medicaid payer status results in

increased 90 day readmission rates specific to hip replacement, increased all cause 90 day comorbidity,

longer length-of-stay with increased resource utilization and total cost compared with a matched cohort

of control patients with other payer profiles.

MATERIALS AND METHODS

The Nationwide Readmissions Database (NRD) was utilized to identify patients who underwent

primary THA (ICD-9 Code 8151) in 2013 as well as corresponding “Medicaid” or “non-Medicaid” payer

statuses. Demographics (age, gender, severity of illness, discharge to skilled facility), fourteen individual

risk factors/comorbidities (smoking, AIDS, alcohol abuse, deficiency anemia, rheumatoid arthritis, chronic

blood loss anemia, congestive heart failure, chronic pulmonary disease, coagulopathy, depression,

diabetes, peripheral vascular disorders, drug abuse, weight loss), readmission rates, length-of-stay, and

direct cost were evaluated. A propensity-score-based matching model was then utilized to control for

baseline confounding variables between payer groups17,18. Propensity scores were estimated using binary

logistic regression with type of insurance as the dependent variable or outcome variable (i.e., the

exposure groups). The independent variables for the propensity score model included covariates

potentially associated with type of insurance, outcome, and type of insurance. Using the resulting logistic

regression equation, the propensity score was calculated as the probability of each patient being in the

Medicaid group.

Using only the propensity score, Medicaid cases were matched one-to-one to other insurance

types using a greedy matching strategy19. Propensity score matching involved the formation of pairs of

Medicaid and non-Medicaid THA patients with similar propensity scores. The most commonly used

method for formation of the pairs is greedy matching using calipers of a specified width20. The propensity

score caliper is the standard deviation of the logit of the propensity score. Calipers of width 0.20 standard

deviations of the logit of the propensity score were used for matching (calipers = 0.2*standard deviation).

In this approach, a Medicaid THA patient is randomly selected and the non-Medicaid THA patient with the

closest propensity score that lies within a fixed distance (the propensity score caliper) of the Medicaid

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subject’s propensity score is selected for matching. If multiple non-Medicaid patients had propensity

scores that were equally close to that of a Medicaid patient, then one of the non-Medicaid patients was

selected at random. Standardized differences were used to assess the balance of confounders between

the two exposure groups.

Standardized differences were defined as the difference in means between the two exposure

groups divided by a measure of the standard deviation of the variable and were computed for both

continuous (i.e., age) and binary covariates. A standardized difference less than 0.1 suggests negligible

difference in the mean or prevalence of a covariate between the two insurance groups in the propensity-

score-matched sample. Evaluation of common support using distributions of propensity scores by types

of insurance. The degree to which the propensity score has been appropriately specified was ascertained

through evaluation of common support. Common support is defined by overlapping distributions of

propensity scores between insurance groups. Overlap in the propensity score distributions indicates the

potential for a patient in the Medicaid group to be in the non-Medicaid insurance group, and that patients

with each level of covariates may have either exposure status (i.e., supporting the assumptions of

exchangeability and positivity). A lack of common support, or a complete separation of propensity scores

without any overlap between the two exposure groups (i.e., Medicaid patients and patients with non-

Medicaid types of insurance) indicates severe differences between the two exposure groups and the

possibility that confounding cannot be reduced using propensity methods. Figures 1-6 (Appendix)

demonstrate the details on assessing the balance produced by the propensity model. The final step

involved estimating the effect of exposure on readmission (overall readmission and hip-related

readmission data were obtained) after THA. Multivariable regression is not necessary since matching on

the propensity scores addressed confounding. The relative risk and its 95% confidence interval for

readmission were calculated based on the two by two table for matched pairs where the outcome is

readmission and the predictor is type of insurance. A relative risk estimate above 1.0 suggests Medicaid

patients were at higher risk of readmission after THA than patients with other types of insurance. Length-

of-stay and total cost comparisons were evaluated using the Wilcoxon signed rank test.

SOURCE OF FUNDING

There was no external funding source for this investigation.

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RESULTS

A total of 5,311 Medicaid and 144,814 non-Medicaid THA patients were identified from the 2013

NRD. A propensity score was estimated from the logistic regression model for each patient. Non-Medicaid patients

(5,311) were propensity-score matched to the 5,311 Medicaid patients. A summary of patient baseline

characteristics and risk factors/comorbidities is provided in Table 1.

The propensity score is a balancing score. The key assessment of the success of the propensity

score adjustment is to demonstrate that the propensity score produced covariate balance between the

exposure groups (Medicaid versus non-Medicaid THA patients). Three approaches were used to assess

covariate balance and propensity score performance. First, the degree to which the propensity score has

been appropriately specified was ascertained through evaluation of common support. Common support

is defined by overlapping distributions of propensity scores by exposure group (see Figure 1). Second, the

boxplots of the propensity scores by quintiles and exposure groups provide additional support of balance

between covariates produced by propensity score matching (Figure 2). Third, balance was examined using

the standardized difference of each covariate between the two exposure groups. All standardized

differences were less than 0.1, suggesting negligible differences in the mean or prevalence of all patient

characteristics and comorbidities between the Medicaid and non-Medicaid groups’. Although there is no

universally agreed upon criterion as to what threshold of the standardized difference can be used to

indicate important imbalance, a standard difference in the mean or prevalence that is less than 0.10 has

often been used in other studies. All of the standardized differences reported in Table 1 meet the 0.1

threshold indicating an improvement in balance after propensity matching compared to the standardized

differences before matching.

Medicaid vs. non-Medicaid payer status yielded statistically significant differences in overall

readmission rates of 28.8% vs. 21.0% (p<0.001, RR=1.37, 95% CI [1.28-1.46]), 90 day readmission for any

reason rates of 14.0% vs. 9.7% (p<0.001, RR=1.45, 95% CI [1.31-1.60]), hip-related reasons for readmission

rates of 6.4% vs. 5.1% (p=0.006, RR=1.25, 95% CI [1.06-1.45]), and 90 day hip-related readmission rates of

2.5% vs. 1.8% (p=0.01, RR=1.38, 95% CI [1.07-1.78]). A relative risk estimate above 1.0 suggests Medicaid

patients were at higher risk of readmission after THA than patients with other types of insurance, which

suggest that the risk of readmission for any reason is 37% higher for Medicaid THA patients compared to

THA patients with other types of insurance; the risk of readmission for any reason is 45% higher for

Medicaid THA patients compared to THA patients with other types of insurance; the risk of hip-related

readmission at any time is 24% higher for Medicaid THA patients compared to THA patients with other

types of insurance; and the risk of hip-related readmission by 90 days is 38% higher for Medicaid THA

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patients compared to THA patients with other types of insurance. Table 2 summarizes the readmission

outcomes in propensity-matched Medicaid versus non-Medicaid patients. Mean length-of-stay was

greater in Medicaid group compared to non-Medicaid group at 4.53 days vs. 3.28 days (p<0.0001) as well

as mean total cost of $71,110 vs. $65,309 (p<0.0001). Tables 3 and 4, respectively, summarizes these

findings. The database 90-day hip readmission rate is 1.3% for all 150,126 patients. Table 5 summarizes

readmission rates for all patients, non-Medicaid patients, and Medicaid patients at 90 days and overall.

DISCUSSION

With continued healthcare reform and the Affordable Care Act (ACA), it is expected that Medicaid

will expand to millions of uninsured Americans21. With this growth, it is expected that the states will be

required to fund approximately 10% of the expansion by 2020. In an effort to decrease cost, APM’s, such

as bundled payments, may become more prevalent. Although the ACA has allowed APM’s for Medicaid

patients in some states, these models have not been readily adopted for arthroplasty patients as cost data

for Medicaid patients is sparse. This study demonstrates that Medicaid payer status is independently

associated with increased morbidity and resource utilization for 90 days following total hip arthroplasty

after adjusting for comorbidities and potential confounders. In addition, Medicaid payer status is

associated with increased length-of-stay, general readmission, and hip-related readmission within 90

days. These findings are consistent with previous orthopaedic literature22-25 and is the largest patient

sample size evaluating Medicaid patients undergoing primary THA from a national standpoint. There are

a few small retrospective cohort studies evaluating Medicaid status with increased 90 day readmission

and one large national inpatient sample study looking at Medicaid inpatient reporting only1,25. This study

is the first to assess a large national database on the impact of Medicaid payer status on resource

utilization via 90 day and overall readmission rates, length-of-stay, and direct cost in THA patients.

The differences in 90 day outcomes after total hip replacement persist after matching Medicaid

patients to non-Medicaid patients. This study design accounts for a wide range of confounding patient

demographics and comorbidities that may be encountered in patients with Medicaid payer status.

Previous studies have revealed several disparities in preoperative patient characteristics that could

influence outcomes. For example, Medicaid patients who undergo total hip replacement are typically

younger, positive smoking history, and increased medical comorbidities. These are potential confounders

that were accounted for in this analysis. Previous studies on this population have been underpowered

and lacked confounding variable control.

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With the increased prevalence of bundled payment programs, health care stakeholders have a

financial incentive to provide high quality care to patients at the lowest cost. With post-discharge care

accounting for a significant portion overall cost, patients who are at increased risk to be discharge to

rehabilitation center or be readmitted within 90 days will significantly increase cost per episode of care9.

Because of increased cost per episode of care in patients with Medicaid status, providers may be hesitant

to take on financial risks associated with Medicaid insurance, thus potentially increasing disparities in

patient access to care. This study justifies further investigation into adjusting reimbursement models for

THA patients based on Medicaid payer status.

The strength of the study is the ability to analyze a large number of patient records and control

for confounding variables through matching. This is a nationwide sample and is representative of clinical

practice. This is the first study to include administrative data on payer status, for 90 days, with sufficient

sample size to avoid beta error. The limitations are those inherent in the analysis of large administrative

databases, such as incomplete data collection, inaccurate diagnostic and procedural coding, and lack of

detailed clinical information. There are also limitations inherent to propensity score matching analysis.

Specifically, propensity score methods only provide the expectation that measured baseline covariates

will be balanced between Medicaid and non-Medicaid groups but make no claim to balance unmeasured

covariates. Psychosocial factors such as income, education level, employment status, and race are not

available in the NRD and thus not available for propensity score matching. Similarly, factors such as

surgeon experience, surgical technique, specific implants, and hospital type were not assessed in this

study. Medicaid patients may also have greater challenge in obtaining care at higher quality hospitals, but

the data is fully de-identified and individual hospital ratings were not available for assessment. Lastly, the

insufficient clinical detail prevents conclusions based on preoperative functional status or the severity of

joint disease that can vary inside of ICD9 Code 8151.

Although this study shows that Medicaid status is an independent risk factor for complications,

readmission, and increased resource utilization, it does not explain why the association exits, nor does it

suggest causation. In the author’s experience, Medicaid patients often have complex social environments

that may lend themselves to complication and readmission. Specifically, patients may only have access to

public transportation and compliance with pre-operative and post-operative appointments can be

difficult and costly. The patient’s housing environment maybe unstable or non-existent and may present

with advanced or neglected hip disease. In some cases, the patient’s post-operative functional status

and/or lack of a care partner may be optimally addressed with post-operative inpatient rehabilitation. As

the Medicaid program does not fund such support, these patients may be prone to an inferior outcome.

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These potential challenges have led to the authors to implement a robust pre-operative social/medical

screening protocol as well as a pre-operative social worker consultation to minimize post-operative issues

with at-risk patients.

The influence of socioeconomic factors on 90 day readmissions and complications is complex and

all potential factor cannot be captured in a study of administrative data. It is important to note that there

are Medicaid patients who are educated, have insight, adequate home support, and may be low-risk

candidates for total hip arthroplasty. However, these socioeconomical factors were not available in the

database and should be considered along with medical comorbidities in reimbursement models. Further

studies are needed to identify other possible psychosocial variables that may impact readmission and cost

of care. These factors should be considered along with medical comorbidities in reimbursement models,

and these models need to be critically evaluated at a continuum to allow policymakers and providers to

implement strategies that will improve care and access for a spectrum of patients. With the continued

growth of APM’s including bundled payments, access to care for individuals with increased risk of

complications, readmission, and discharge to facility will continue to be an issue. Physicians and hospitals

may potentially have a disincentive on patient populations who require increased resource utilization.

Medicaid status in this study was predictive of increased overall and 90 day readmission, length-of-stay,

and direct cost after THA. Risk adjustment models accounting for Medicaid status are necessary to avoid

decreased access to care for this patient population and avoid financial penalty for physician and hospital

alike.

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REFERENCES:

1. Browne JA, Novicoff WM, D'apuzzo MR. Medicaid payer status is associated with in-hospital morbidity and resource utilization following primary total joint arthroplasty. J Bone Joint Surg Am. 2014;96(21):e180.

2. Medicaid Eligibility Criteria. http://www.medicaid.gov/Medicaid-CHIP-Program-Information/By-Topics/Eligibility/Eligibility.html. Accessed 2014 Jun 19.

3. Congressional Budget Office. Estimates for the insurance coverage provisions of the Affordable Care Act updated for the recent Supreme Court decision. 2012 Jul.http://cbo.gov/sites/default/files/cbofiles/attachments/43472-07-24-2012-CoverageEstimates.pdf. Accessed 2014 Jun 19.

4. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007;89(4):780-5.

5. Centers for Medicare and Medicaid Services. New Medicare data available to increase transparency on hospital utilization. https://www.cms.gov/Newsroom/MediaReleaseDatabase/Fact-sheets/2015-Fact-sheets-items/2015-06-01.html

6. Iorio R, Clair AJ, Inneh IA, Slover JD, Bosco JA, Zuckerman JD. Early Results of Medicare's Bundled Payment Initiative for a 90-Day Total Joint Arthroplasty Episode of Care. J Arthroplasty. 2016;31(2):343-50.

7. Mechanic RE. Mandatory Medicare Bundled Payment--Is It Ready for Prime Time?. N Engl J Med. 2015;373(14):1291-3.

8. Iorio R, Bosco J, Slover J, Sayeed Y, Zuckerman JD. Single Institution Early Experience with the Bundled Payments for Care Improvement Initiative. J Bone Joint Surg Am. 2017;99(1):e2.

9. Slover JD. You Want a Successful Bundle: What About Post-discharge Care?. J Arthroplasty. 2016;31(5):936-7.

10. Iorio R. Strategies and tactics for successful implementation of bundled payments: bundled payment for care improvement at a large, urban, academic medical center. J Arthroplasty. 2015;30(3):349-50.

11. Kamath AF, Courtney PM, Bozic KJ, Mehta S, Parsley BS, Froimson MI. Bundled Payment in Total Joint Care: Survey of AAHKS Membership Attitudes and Experience with Alternative Payment Models. J Arthroplasty. 2015;30(12):2045-56.

12. Calvillo-king L, Arnold D, Eubank KJ, et al. Impact of social factors on risk of readmission or mortality in pneumonia and heart failure: systematic review. J Gen Intern Med. 2013;28(2):269-82.

13. Lapar DJ, Bhamidipati CM, Mery CM, et al. Primary payer status affects mortality for major surgical operations. Ann Surg. 2010;252(3):544-50.

14. Lyon SM, Benson NM, Cooke CR, Iwashyna TJ, Ratcliffe SJ, Kahn JM. The effect of insurance status on mortality and procedural use in critically ill patients. Am J Respir Crit Care Med. 2011;184(7):809-15.

15. Stone ML, Lapar DJ, Mulloy DP, et al. Primary payer status is significantly associated with postoperative mortality, morbidity, and hospital resource utilization in pediatric surgical patients within the United States. J Pediatr Surg. 2013;48(1):81-7.

16. Inneh IA. The Combined Influence of Sociodemographic, Preoperative Comorbid and Intraoperative Factors on Longer Length of Stay After Elective Primary Total Knee Arthroplasty. J Arthroplasty. 2015;30(11):1883-6.

17. Rosenbaum PR, Rubin DB. The central role of the propensity score in observational studies for causal effects. Biometrika. 1983;70:41-55.

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18. Rubin DB. The design versus the analysis of observational studies for causal effects: parallels with the design of randomized trials. Stat Med. 2007;26(1):20-36.

19. Bergstralh EJ, Konsanke JL. Computerized matching of cases to controls. In: Technical reports series, number 56. Rochester, MN: Mayo Clinic Department of Health Sciences Research;1995.

20. Austin PC. An Introduction to Propensity Score Methods for Reducing the Effects of Confounding in Observational Studies. Multivariate Behav Res. 2011;46(3):399-424.

21. Ayanian JZ, Ehrlich GM, Grimes DR, Levy H. Economic Effects of Medicaid Expansion in Michigan. N Engl J Med. 2017;376(5):407-410.

22. Freburger JK, Holmes GM, Ku LJ, Cutchin MP, Heatwole-shank K, Edwards LJ. Disparities in post-acute rehabilitation care for joint replacement. Arthritis Care Res (Hoboken). 2011;63(7):1020-30.

23. Courtney PM, Huddleston JI, Iorio R, Markel DC. Socioeconomic Risk Adjustment Models for Reimbursement Are Necessary in Primary Total Joint Arthroplasty. J Arthroplasty. 2017;32:1-5.

24. Rozell JC, Courtney PM, Dattilo JR, Wu CH, Lee GC. Should All Patients Be Included in Alternative Payment Models for Primary Total Hip Arthroplasty and Total Knee Arthroplasty?. J Arthroplasty. 2016;31(9 Suppl):45-9.

25. Courtney PM, Edmiston T, Batko B, Levine BR. Can Bundled Payments Be Successful in the Medicaid Population for Primary Joint Arthroplasty? J Arthroplasty. 2017 May 25. pii: S0883-5403(17)30474-6. doi: 10.1016/j.arth.2017.05.035. [Epub ahead of print].

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Table 1. Characteristics of the total hip arthroplasty (ICD 9 code 8151) patients from the 2013

Nationwide Readmissions Database (NRD)

Before Propensity

Matching After Propensity Matching

Risk Factor

Medicaid n=5,312

Other Insurance n=144,814

P Standardized difference

Medicaid n=5,311

Other Insurance

n=5,311

P† Standardized difference‡

Age, years (mean ± SD)

52.0 ± 10 66.0 ± 12 <.0001 1.279 52.0 ± 10 52 .8 ± 11 <.0001 0.023

Female sex 2,798 (52.7%) 81,259 (56.1%)

<.0001 0.069 2,798 (52.7%)

2,776 (52.3%) 0.3271 0.008

Severity of Illness (major

/extreme loss vs other)

453 (8.5%) 8,687 (6.0%) <.0001 0.098 453 (8.5%) 420 (7.9%) 0.1036 0.023

Discharged to skilled facility

1,152 (21.7%) 38,898 (26.9%)

<.0001 0.121 1,152 (21.7%)

1,145 (21.6%) 0.7554 0.003

Smoking 2,243 (42.2%) 36,447 (25.2%)

<.0001 0.367 2,242 (42.2%)

2,235 (42.1%) 0.7634 0.003

Comorbidities

AIDS 30 (0.6%) 149 (0.1%) <.0001 0.080 30 (0.6%) 20 (0.4%) 0.1317 0.028

Alcohol abuse 326 (6.1%) 2,504 (1.7%) <.0001 0.228 326 (6.1%) 291 (5.5%) 0.0348 0.028

Deficiency anemia

705 (13.3%) 16,550 (11.4%)

<.0001 0.056 705 (13.3%) 693 (13.0%) 0.5582 0.007

Rheumatoid arthritis

269 (5.1%) 5,778 (4.0%) <.0001 0.052 269 (5.1%) 242 (4.6%) 0.0668 0.024

Chronic blood loss anemia

62 (1.2%) 1,881 (1.3%) 0.4041 0.012 62 (1.2%) 42 (0.8%) 0.0098 0.038

Congestive heart failure

115 (2.2%) 3,866 (2.7%) 0.0245 0.033 115 (2.2%) 89 (1.7%) 0.0291 0.036

Chronic pulmonary

disease

1,222 (23.0%) 20,400 (14.1%)

<.0001 0.231 1,222 (23.0%)

1,204 (22.7%) 0.4227 0.008

Coagulopathy 137 (2.6%) 3,511 (2.4%) 0.4724 0.010 137 (2.6%) 124 (2.3%) 0.3285 0.016

Depression 915 (17.2%) 16,964 (11.7%)

<.0001 0.157 914 (17.2%) 902 (17.0%) 0.5619 0.006

Diabetes 776 (14.6%) 21,316 (14.7%)

0.8223 0.003 776 (14.6%) 780 (14.7%) 0.8415 0.002

Peripheral vascular disorders

62 (1.2%) 4,217 (2.9%) <.0001 0.124 62 (1.2%) 39 (0.7%) 0.0032 0.045

Drug abuse 290 (5.5%) 1,140 (0.8%) <.0001 0.271 289 (5.4%) 226 (4.3%) 0.0002 0.055

Weight Loss 68 (1.3%) 1,120 (0.8%) <.0001 0.050 68 (1.3%) 53 (1.0%) 0.1508 0.027 †McNemar’s test (a chi-square test for paired proportions). The difference in paired proportions is small for all covariates but statistically significant for several covariates due to the large sample size. ‡A standardized difference less than 0.10 suggests negligible difference in the mean or prevalence of a covariate between the two insurance groups.

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Table 2: Readmission outcomes in propensity-matched Medicaid versus other types of insurance patients

A. Readmission for any reason

Medicaid Other insurance types Readmitted Not Readmitted Total

Readmitted 363a 758b 1,121 Not Readmitted 1169c 3021d 4,190

Total 1,532 3,779 5311 pairs

(n) Paired proportion Medicaid, Pm: a+c/n 1532/5311 (0.288) Paired proportion Other, P0: a+b/n 1121/5311 (0.211) Relative Risk=[a+c]/[a+b] (95% Confidence interval) 1.37 (1.28, 1.46), P<0.001

B. 90 day readmission for any reason

Medicaid Other insurance types Readmitted Not Readmitted Total

Readmitted 101a 414b 515 Not Readmitted 646c 4150d 4,796

Total 747 4,564 5311 pairs

(n) Paired proportion Medicaid, Pm: a+c/n 747/5311 (0.140) Paired proportion Other, P0: a+b/n 515/5311 (0.097) Relative Risk (95% Confidence interval) 1.45 (1.31, 1.60), P <0.001

C. Hip readmission

Medicaid Other insurance types Readmitted Not Readmitted Total

Readmitted 21a 252b 273 Not Readmitted 318c 4720d 5,038

Total 339 4,972 5311 pairs

(n) Paired proportion Medicaid, Pm: a+c/n 339/5311 (0.0638) Paired proportion Other, P0: a+b/n 273 /5311 (.0514) Relative Risk (95% Confidence interval) 1.24 (1.06, 1.45), P=0.006

D. 90 day hip readmission

Medicaid

Other insurance types Readmitted Not Readmitted Total Readmitted 4a 94b 98

Not Readmitted 131c 5082d 5,213

Total 135 5,176 5311 pairs

(n) Paired proportion Medicaid, Pm: a+c/n 135/5311 (0.025) Paired proportion Other, P0: a+b/n 98/5311 (0.018) Relative Risk (95% Confidence interval) 1.38 (1.07, 1.78) p=0.01

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E. Summary of readmission outcomes in propensity matched Medicaid vs other types of insurance patients

Medicaid† n=5,311

Other insurance†

n=5,311 P value Relative Risk

(95% CI)

Readmission for any reason 28.8% 21.0% <0.001 1.37 (1.28, 1.46) 90-day readmission for any reason

14.0% 9.7% <0.001 1.45 (1.31, 1.60)

Hip readmission 6.4% 5.1% 0.006 1.24 (1.06, 1.45) 90-day hip readmission 2.5% 1.8% 0.01 1.38 (1.07, 1.78)

†For the matched sample, the values reported are the percentages.

Table 3. Comparison of length-of-stay after THA between Medicaid and Non-Medicaid patients (n=5,311)

Medicaid Other insurance Difference p-value (95% CI) (95% CI) (95% CI)

Length-of-stay

Median 3 ( 3 - 3) 3 ( 3 - 3) 0 ( 0 - 1) <0.0001* Mean 4.53 (4.31, 4.75) 3.28 (3.19, 3.37) 1.25 (1.01, 1.49) <0.0001†

Standard deviation 8.29 3.35

Inter quartile range 2 1

† P-value from paired t-test *P-value from Wilcoxon signed rank test

Table 4. Comparison of total cost after THA between Medicaid and Non-Medicaid patients (n=5,061)

Medicaid Other insurance Difference p-value (95% CI) (95% CI) (95% CI)

Total cost

Median 58,674 (57,609 – 59,704)

54,936

(54,094 – 55,939)

3,825 (2,303 – 5,013) <0.0001*

Mean 71,110 (69,490 – 72,730)

65,309

(64,150 – 66,467)

5,802 (3,855 –

7,748)

<0.0001†

Standard deviation 58,784 42,044 70,619 Inter quartile range 44,368 39,751 56,928

† P-value from paired t-test *P-value from Wilcoxon signed rank test

Table 5. Readmission rates for all, non-Medicaid, and Medicaid patients at 90 days and overall.

All Patients n=150,126

Non-Medicaid n=144,814

Medicaid n=5,312

A. 90-day hip readmission 1,953/150,126 (1.3%)

1,818/144,814 (1.3%)

135 / 5,312 (2.5%)

B. Any hip readmission 5,821/150,126 (3.9%)

5,482/144,814 (3.8%)

339 / 5,312 (6.4%)

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Figure 1: Evaluation of common support using distributions of propensity scores by type of insurance

The degree to which the propensity score has been appropriately specified was ascertained through evaluation of common support. Common support is defined by overlapping distributions of propensity scores between insurance groups. Overlap in the propensity score distributions indicates the potential for a patient in the Medicaid group to be in the ‘Other’ insurance group, and that patients with each level of covariates may have either exposure status (i.e. supporting the assumptions of exchangeability and positivity)1. A lack of common support, or a complete separation of propensity scores without any overlap between the two exposure groups (i.e, Medicaid patients and patients with ‘Other’ types of insurance) indicates severe differences between the two exposure groups and the possibility that confounding cannot be reduced using propensity methods2.

This boxplot demonstrates overlapping ranges of the boxplots of propensity scores between Medicaid patients and patients with ‘Other’ types of insurance, which indicates that the propensity model exhibits common support. Circles within each boxplot denote the mean score. The middle line within the box represents the median, the top line represents the 75th percentile and the bottom line represents the 25th percentile. The upper fence is defined as the third quartile (represented by the upper edge of the box) plus 1.5 times the interquartile range. The lower fence is defined as the first quartile (represented by the lower edge of the box) minus 1.5 times the interquartile range. Observations outside the fences are identified with an open circle.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0Pr

open

sity

Sco

reMedicaid (n=5311)Other insurance(n=5311)

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References:

1. Hernan MA, Robins JM. Estimating causal effects from epidemiological data. J Epidemiol Community Health. 2006;60(7):578-586.

2. Harder VS, Stuart EA, Anthony JC. Propensity score techniques and the assessment of measured covariate balance to test causal associations in psychological research. Psychol Methods. 2010;15(3):234-249.

Figure 2: Distribution of propensity scores by quintiles and type of insurance in matched dataset: non-Medicaid vs Medicaid

Boxplot demonstrates distribution of propensity scores among Medicaid patients and patients with other types of insurance by quintiles of propensity scores. Circles within each boxplot denote the mean score. The middle line within the box represents the median, the top line represents the 75th percentile and the bottom line represents the 25th percentile. The upper fence is defined as the third quartile (represented by the upper edge of the box) plus 1.5 times the interquartile range. The lower fence is defined as the first quartile (represented by the lower edge of the box) minus 1.5 times the interquartile range. Observations outside the fences are identified with an open circle.

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Figure 3: Propensity score distribution (density) in matched database: non-Medicaid vs Medicaid

Figure 4: Propensity score distribution (percentile) in matched dataset: non-Medicaid vs Medicaid

Propensity score distribution in matched dataset:matched (no medicaid) vs Medicaid.

Normal

Estimated Probability

medicaid = 1medicaid = 0

-0.2 0.0 0.2 0.4-0.2 0.0 0.2 0.40

1

2

3

Den

sity

Propensity score distribution in matched dataset:matched (no medicaid) vs Medicaid.

Normal

Estimated Probability

medicaid = 1medicaid = 0

-0.25 0.00 0.25 0.50 0.75-0.25 0.00 0.25 0.50 0.750

5

10

15

20

25

Per

cent

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Figure 5: Distribution of propensity scores by quintiles and type of insurance in unmatched dataset: non-Medicaid vs Medicaid

Figure 6: Propensity score distribution in unmatched dataset: non-Medicaid vs Medicaid

-0.2 0.0 0.2 0.4

0

2

4

6

8D

ensi

tyNon-MedicaidMedicaid-Density

Propensity score distribution in original dataset:unmatched (no medicaid) vs Medicaid.

Propensity score distribution in original dataset:unmatched (no medicaid) vs Medicaid.

Normal

Estimated Probability

medicaid = 1medicaid = 0

-0.25 0.00 0.25 0.50 0.75-0.25 0.00 0.25 0.50 0.750

10

20

30

40

Per

cent

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2017 - 2018 Orthopaedic Surgery Residents

PGY4 – PGY1

P G Y

4

Briggs Ahearn Medical University of

South Carolina College of Medicine

Hometown: Georgetown, SC

Ian Gao Northwestern University

The Feinberg School of Medicine

Hometown: Clemson, SC

Sandra Hobson University of Virginia School of Medicine

Hometown: Lynchburg, VA

Rishin Kadakia Vanderbilt University School of Medicine

Hometown: Nashville, TN

Jeffrey Konopka Indiana University School of Medicine

Hometown: Greenwood, IN

Timothy McCarthy Creighton University

School of Medicine Hometown:

W. Des Moines, IA

P G Y

3

Adam Boissonneault

Trinity College Dublin, Ireland

Hometown: Long Valley, NJ

Zach Grabel Brown University

Alpert Medical School Hometown:

Palm Beach Gardens, FL

Greg Kurkis University of Virginia School of Medicine

Hometown: Roswell, GA

Nick Patel Emory University

School of Medicine Hometown:

North East, MD

Dale Segal Florida International

University Hometown: Queens, NY

David Shau Vanderbilt

University School of Medicine

Hometown: Flower Mound, TX

P G Y

2

Russell Holzgrefe University of Virginia

Hometown: Tucker, GA

Thomas Neustein Emory University

Hometown: Demarest, NJ

Keith Orland Medical University of

South Carolina Hometown:

Charlotte, NC

Andrew Schwartz Albert Einstein

College of Medicine Hometown:

West Chester, OH

R. Matt Wham University of Tennessee

Hometown: Oak Ridge, TN

Jacob Wilson Medical College of

Wisconsin Hometown:

Richmond, OH

P G Y

1

William Godfrey Emory University

Hometown: Atlanta, GA

Matthew Lunati University of Texas Health

at San Antonio Hometown:

Sandy Springs, GA

Jeremy Pflederer University of Illinois College of Medicine

Hometown: Tremont, IL

Huai Ming Phen Emory University

Hometown: Ilford, UK

William Runge University of North

Carolina at Chapel Hill Hometown:

Ann Arbor, Michigan

Weilong Jeff Shi Emory University

Hometown: Atlanta, GA

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Emory Orthopaedics Research & Surgical Faculty Scott Boden Professor & Interim Chairman, Spine Thomas L. Bradbury Assistant Professor, Adult Reconstruction Dheera Ananthakrishnan Assistant Professor, Spine Jason Bariteau Assistant Professor, Foot & Ankle Robert W. Bruce, Jr. Associate Professor, Pediatric Orthopaedics Hicham Drissi Professor & Vice Chairman, Research Greg Erens Assistant Professor, Adult Reconstruction Nicholas Fletcher Associate Professor, Pediatric Orthopaedics Matthew Gary Assistant Professor, Spine George Guild Assistant Professor, Adult Reconstruction Michael Gottschalk Assistant Professor, Hand & Upper Extremity Kyle Hammond Assistant Professor, Sports Medicine John G. Heller Baur Professor of Orthopaedic Surgery, Spine William Hutton, Ph.D Professor, Research Edward Jackson, III Assistant Professor, Sports Medicine Spero Karas Associate Professor, Sports Medicine Sameh Labib Associate Professor, Sports Medicine/Foot & Ankle John Louis-Ugbo Assistant Professor, Foot & Ankle Michael Maceroli Assistant Professor, Trauma T. Scott Maughon Assistant Professor, Sports Medicine Gary McGillivary Assistant Professor, Hand & Upper Extremity Clifton Meals Assistant Professor, Hand & Upper Extremity Keith Michael Assistant Professor, Spine David Monson Assistant Professor, Musculoskeletal Oncology Thomas Moore, Jr. Assistant Professor, Trauma Shervin Oskouei Assistant Professor, Musculoskeletal Oncology Diane Payne Assistant Professor, Trauma/Hand & Upper Extremity Mathew Pombo Assistant Professor, Sports Medicine Steven Presciutti Assistant Professor, Spine Daniel Refai Assistant Professor, Spine Nickolas Reimer Assistant Professor, Musculoskeletal Oncology William Reisman Assistant Professor, Trauma John Rhee Associate Professor, Spine , Neurosurgery James R. Roberson Robert P. Kelly Professor, Adult Reconstruction Gerald Rodts Professor, Spine , Neurosurgery Christopher Sadlack Assistant Professor, Adult Reconstruction Mara Schenker Assistant Professor, Trauma Richard Thomas Assistant Professor, Trauma Nick Willett , PhD Assistant Professor, Research Brent Wise Assistant Professor, Trauma John W. Xerogeanes Professor, Sports Medicine S. Tim Yoon Professor, Spine

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Kelly Day Visiting Professors

1978 William Murray MD Professor & Chairman of The Department of Orthopedic Surgery at UCSF.

1979 Robert E. Leach MD Boston University

1980 Carl L. Nelson MD Chairman of the Department of Orthopaedic Surgery at the University of Arkansas for Medical Science

1981 Sir John Charnley Wrightington Hospital Professor Emeritus of the University of Manchester, the Royal College of Surgeons of England and Ireland, and the Universities of Edinburgh and Glasgow.

1982 Howard H. Steel MD Shriner’s Hospital-Philadelphia

1983 Robert H. Fitzgerald, Jr. MD Chairman - Wayne State University

1984 Joseph Schatzker MD Professor Emeritus of Surgery at the University of Toronto

1985 Larry Matthews MD The University of Michigan

1986 John P. Kostuik MD Professor Johns Hopkins University School of Medicine

1987 Richard H. Gelberman MD Washington University, Department of Orthopaedic Surgery

1988 J. Leonard Goldner MD Duke University

1989 Henry J. Mankin MD Massachusetts General Hospital

1990 Bernard F. Morrey MD Professor & Chairman, of Orthopaedics at the Mayo Clinic

1991 Gary G. Poehling MD Professor of Orthopaedic Surgery at Bowman Gray School of Medicine

1992 Michael W. Chapman MD Professor & Chairman,

Department of Orthopaedic Surgery University of California at Davis

1993 Michael F. Schafer MD Ryerson Professor & Chairman Department of Orthopaedic Surgery Northwestern School of Medicine

1994 James R. Urbaniak MD Virginia Flowers Baker Professor & Chief of Orthopaedic Surgery, Duke University Medical Center

1995 Dan M. Spangler MD Professor & Chairman of Orthopaedic Surgery & Rehabilitation, Vanderbilt University

1996 James H. Herndon MD David Silver Professor & Chairman of Orthopaedic Surgery, University Pittsburgh’s Medical School & Chief of Orthopaedics & Rehabilitation at the UPMC.

1997 S. Terry Canale MD Professor, Department of Orthopaedic Surgery, University of Tennessee College of Medicine.

1998 Angus M. McBryde, Jr. MD Professor & Chairman, Orthopaedic Surgery,The Medical University of South Carolina.

1999 L. Andrew Koman MD Professor & Chairman, Department of Orthopaedic Surgery, Duke University Medical Center

2000 Louis U. Bigliani MD Frank E. Stinchfield Professor & Chairman Department of Orthopaedic Surgery College of Physicians & Surgeons

2001 Robert S. Adelaar MD Professor & Vice-Chairman, Department of Orthopaedic Surgery Medical College of Virginia

2002 John S. Gould MD Alabama Sports Medicine

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2003 Freddie H. Fu MD Professor & Chairman, Department of Orthopaedic Surgery University of Pittsburgh

2004 Peter Stern MD

Professor & Chairman, University of Cincinnati

2005 James N. Weinstein DO

Chairman Department of Orthopaedics Dartmouth

2006 Marc F. Swiontkowski MD

Chairman Department of Orthopaedics University of Minnesota

2007 Michael Coughlin MD

Coughlin Foot and Ankle Clinic at St. Alphonsus Hospital, Boise, Idaho

2008 Michael Simon MD

Chairman, Department of Orthopaedics University of Chicago

2009 Richard J. Hawkins MD,

Clinical Professor, University of Colorado Clinical Professor, Team Physician: Denver Broncos, Colorado Rockies & UT Southwestern. Principal, Steadman Hawkins Clinic of the Carolinas

2010 Joseph A. Buckwater, MD

Professor & Head of The Department of Orthopaedic Surgery

2011 Jesse B. Jupiter, MD

Professor of Orthopaedic Surgery at Massachusetts General Hospital

2012 J.A. “Tony” Herring, MD

Chief of Staff, Emeritus at Texas Scottish Rite Professor of Orthopaedic Surgery University of Texas Southwestern Medical School

2013 Steven Garfin, MD

Professor and Chair Department of Orthopaedic Surgery at UCSD

2014 William Levine, MD Frank E. Stinchfield Professor and Chairman, Department of Orthopedic Surgery Columbia University Medical Center

2015 Kevin Bozic, MD, MBA Inaugural Chair of the Department of Surgery and Perioperative Care, and Professor of Orthopaedic Surgery at the Dell Medical School University of Texas at Austin

2016 Samir Mehta, MD, MBA Associate Professor, Department of Orthopaedic Surgery Chief, Orthopaedic Trauma and Fracture Service University of Pennsylvania

2017 Mark E. Baratz, MD, M Program Director, Orthopaedic Surgery Hand Fellowship, Clinical Professor and Vice Chairman, Department of Orthopaedics, University of Pittsburgh Medical Center

2018 Michael Vitale, MD, MPH Ana Lucia Professor of Pediatric Orthopaedic Surgery & Neurosurgery Vice Chair, Quality & Strategy,

Orthopaedic Surgery, Columbia University Medical Center

at the University of Iowa Hospitals & Clinic

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FACULTY PUBLICATIONS Peer-Reviewed Journals: 2016-2018 Functional and clinical outcomes of total ankle arthroplasty in elderly compared to younger patients. Tenenbaum S, Bariteau J, Coleman S, Brodsky J. Foot Ankle Surg. 2017 Jun;23(2):102-107. doi: 10.1016/j.fas.2016.09.005. Epub 2016 Oct 17. PMID: 28578792 Gait abnormalities in patients with chronic ankle instability can improve following a non-invasive biomechanical therapy: a retrospective analysis. Tenenbaum S, Chechik O, Bariteau J, Bruck N, Beer Y, Falah M, Segal G, Mor A, Elbaz A. J Phys Ther Sci. 2017 Apr;29(4):677-684. doi: 10.1589/jpts.29.677. Epub 2017 Apr 20. PMID: Population Health Management: Is There Any Role for Orthopaedics?: An AOA Critical Issues Symposium. Boden SD, Smith BT, Handley M. J Bone Joint Surg Am. 2017 May 3;99(9):e45. doi: 10.2106/JBJS.16.00875.PMID: 28463927 Minimally Invasive Spine Surgery (MISS) in China. Tian W, Boden SD. Spine (Phila Pa 1976). 2016 Oct;41 Suppl 19:B1. No abstract available.PMID: 27653008 Musculoskeletal Workforce Needs: Are Physician Assistants and Nurse Practitioners the Solution? AOA Critical Issues. Day CS, Boden SD, Knott PT, O'Rourke NC, Yang BW. J Bone Joint Surg Am. 2016 Jun 1;98(11):e46. doi: 10.2106/JBJS.15.00950. Review.PMID: 27252443 Modified Frailty Index Is an Effective Risk Assessment Tool in Primary Total Hip Arthroplasty. Bellamy JL, Runner RP, Vu CCL, Schenker ML, Bradbury TL, Roberson JR. J Arthroplasty. 2017 May 4. pii: S0883-5403(17)30397-2. doi: 10.1016/j.arth.2017.04.056. [Epub ahead of print] PMID: 28559198 A Validated Single-View Radiographic Alternative to Computed Tomography for the Measurement of Femoral Anteversion: A Method-Comparison Study. Boissonneault AR, Hiranaka T, Roberson JR, Bradbury TL. J Arthroplasty. 2017 Mar;32(3):1018-1023. doi: 10.1016/j.arth.2016.09.016. Epub 2016 Sep 28. PMID: 27816368 Trends in Primary and Revision Hip Arthroplasty Among Orthopedic Surgeons Who Take the American Board of Orthopedics Part II Examination. Eslam Pour A, Bradbury TL, Horst PK, Harrast JJ, Erens GA, Roberson JR. J Arthroplasty. 2016 Jul;31(7):1417-21. doi: 10.1016/j.arth.2015.12.045. Epub 2016 Feb 26. PMID: 27004678 rends in primary and revision knee arthroplasty among orthopaedic surgeons who take the American Board of Orthopaedics part II exam. Pour AE, Bradbury TL, Horst P, Harrast JJ, Erens GA, Roberson JR. Int Orthop. 2016 Oct;40(10):2061-2067. Epub 2016 Feb 22. PMID: 26899485 Spine (Phila Pa 1976). 2016 Dec 1;41(23):E1408-E1414.Posterolateral Fusion Versus Interbody Fusion for Degenerative Spondylolisthesis: A Systematic Review and Meta-Analysis. McAnany SJ, Baird EO, Qureshi SA, Hecht AC, Heller JG, Anderson PA. Posterior Malleolus Fractures.Tenenbaum S, Shazar N, Bruck N, Bariteau J.Orthop Clin North Am. 2017 Jan;48(1):81-89. doi: 10.1016/j.ocl.2016.08.004. Epub 2016 Oct 28. Review.PMID: 27886685 Abnormalities of gait caused by ankle arthritis are improved by ankle arthrodesis. Brodsky JW, Kane JM, Coleman S, Bariteau J, Tenenbaum S. Bone Joint J. 2016 Oct;98-B(10):1369-1375. PMID: 27694591

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Costs Associated With Geriatric Ankle Fractures. Kadakia RJ, Ahearn BM, Tenenbaum S, Bariteau JT.Foot Ankle Spec. 2017 Feb;10(1):26-30. doi: 10.1177/1938640016666919. Epub 2016 Sep 20. PMID: 27604512 Orthopedic Surgery Resident Debt Load and Its Effect on Career Choice. Johnson JP, Cassidy DB, Tofte JN, Bariteau JT, Daniels AH. Orthopedics. 2016 May 1;39(3):e438-43. doi: 10.3928/01477447- 20160315-01. Epub 2016 Mar 29. PMID: 27018605 Return to Play After Shoulder Instability Surgery in National Collegiate Athletic Association Division I Intercollegiate Football Athletes.Robins RJ, Daruwalla JH, Gamradt SC, McCarty EC, Dragoo JL, Hancock RE, Guy JA, Cotsonis GA, Xerogeanes JW; ASP Collaborative Group, Greis PE, Tuman JM, Tibone JE, Javernick MA, Yochem EM, Boden SA, Pilato A, Miley JH.Am J Sports Med. 2017 May 1:363546517705635. doi: 10.1177/0363546517705635. [Epub ahead of print]PMID: 28557527 Increasing hip and knee flexion during a drop-jump task reduces tibiofemoral shear and compressive forces: implications for ACL injury prevention training.Tsai LC, Ko YA, Hammond KE, Xerogeanes JW, Warren GL, Powers CM.J Sports Sci. 2016 Dec 23:1-7. doi: 10.1080/02640414.2016.1271138. [Epub ahead of print]PMID: 28006992 Minimally Invasive Quadriceps Tendon Harvest and Graft Preparation for All-Inside Anterior Cruciate Ligament Reconstruction.Slone HS, Ashford WB, Xerogeanes JW.Arthrosc Tech. 2016 Sep 19;5(5):e1049-e1056. eCollection 2016 Oct.PMID: 27909674 Free PMC Article Liposomal Bupivacaine for Pain Control After Anterior Cruciate Ligament Reconstruction: A Prospective, Double-Blinded, Randomized, Positive-Controlled Trial. Premkumar A, Samady H, Slone H, Hash R, Karas S, Xerogeanes J. Am J Sports Med. Arthroscopic Reduction and Internal Fixation (ARIF) of a Comminuted Posterior Talar Body Fracture. Kadakia R, Konopka J, Rodik T, Ahmed S, Labib SA. Foot Ankle Spec. 2017 Jan 1:1938640016685148. doi: 10.1177/1938640016685148. [Epub ahead of print]PMID: 28068792 Outcomes of ACL Reconstruction With Fixed Versus Variable Loop Button Fixation.Wise BT, Patel NN, Wier G, Labib SA.Orthopedics. 2017 Mar 1;40(2):e275-e280. doi: 10.3928/01477447-20161116-04. Epub 2016 Nov 23.PMID: 27874911 Unilateral Spinous Process Non-Covering Hook Type Patient-Specific drill template for thoracic pedicle screw fixation: A Pilot Clinical Trial and Template Classification. Kim SB, Won Y, Yoo HJ, Sin LJ, Rhee JM, Lee SW, Lee GS. Spine (Phila Pa 1976). 2017 Jan 13. doi: 10.1097/BRS.0000000000002067. [Epub ahead of print] PMID: 28092341 Is it "in" or "out"? The Optimal Fluoroscopic Views for Intraoperative Determination of Proper Lateral Mass Screw Placement.Kim SB, Rhee JM, Oh BH, Won YG, Jung Y, Park KY, Hutton WC, Kim C. Spine (Phila Pa 1976). 2016 Dec 2. [Epub ahead of print] PMID: 27922577 "Inline" Axial Reconstructed CT Scans Provide a Significantly Larger Assessment of C2 Pedicle Diameter for Screw Placement Compared With "Standard" Axial Scans: Implications for Surgical Planning. Vizurraga DE, Rhee JM, Borden TC, Mansour AS. Clin Spine Surg. 2016 Jun 27. [Epub ahead of print] PMID: 27352376

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Surgical management of Gorham disease involving the upper cervical spine with occipito-cervical-thoracic fusion: a case report. Schell A, Rhee JM, Allen A, Andras L, Zhou F. Spine J. 2016 Jul;16(7):e467-72. doi: 10.1016/j.spinee.2016.02.020. Epub 2016 Mar 11.PMID: 26975457 Where should a laminoplasty start? The effect of the proximal level on post-laminoplasty loss of lordosis. Michael KW, Neustein TM, Rhee JM. Spine J. 2016 Jun;16(6):737-41. doi: 10.1016/j.spinee.2016.01.188. Epub 2016 Jan 28. PMID: 26828011 A Retrospective Analysis of Complications Associated With Bone Morphogenetic Protein 2 in Anterior Lumbar Interbody Fusion. Hindoyan K, Tilan J, Buser Z, Cohen JR, Brodke DS, Youssef JA, Park JB, Yoon ST, Meisel HJ, Wang JC. Global Spine J. 2017 Apr;7(2):148-153. doi: 10.1177/2192568217694010. Epub 2017 Apr 6. PMID: 28507884 Free PMC Article Autograft versus Allograft for Cervical Spinal Fusion: A Systematic Review. Tuchman A, Brodke DS, Youssef JA, Meisel HJ, Dettori JR, Park JB, Yoon ST, Wang JC. Global Spine J. 2017 Feb;7(1):59-70. doi: 10.1055/s-0036-1580610. Epub 2017 Feb 1. Review. PMID: 28451511 Free PMC Article Ultrasonographic and Clinical Characteristics of Schwannoma of the Hand. Lee SJ, Yoon ST. Clin Orthop Surg. 2017 Mar;9(1):91-95. doi: 10.4055/cios.2017.9.1.91. Epub 2017 Feb 13. PMID: 28261433 Free PMC Article Analysis of Recombinant Human Bone Morphogenetic Protein-2 Use in the Treatment of Lumbar Degenerative Spondylolisthesis.Yao Q, Cohen JR, Buser Z, Park JB, Brodke DS, Meisel HJ, Youssef JA, Wang JC, Yoon ST. Global Spine J. 2016 Dec;6(8):749-755. Epub 2016 Mar 25. PMID: 27853658 Free PMC Article Perioperative Complications of Cervical Spine Surgery: Analysis of a Prospectively Gathered Database through the Association for Collaborative Spinal Research. Leckie S, Yoon ST, Isaacs R, Radcliff K, Fessler R, Haid R Jr, Traynelis V.Global Spine J. 2016 Nov;6(7):640-649. Epub 2015 Dec 15. PMID: 27781183 Free PMC Article Complications Related to the Recombinant Human Bone Morphogenetic Protein 2 Use in Posterior Cervical Fusion. Takahashi S, Buser Z, Cohen JR, Roe A, Myhre SL, Meisel HJ, Brodke DS, Yoon ST, Park JB, Wang JC, Youssef JA.Clin Spine Surg. 2016 Sep 14. [Epub ahead of print] PMID: 27632774 Iliac Crest Bone Graft versus Local Autograft or Allograft for Lumbar Spinal Fusion: A Systematic Review.Tuchman A, Brodke DS, Youssef JA, Meisel HJ, Dettori JR, Park JB, Yoon ST, Wang JC. Global Spine J. 2016 Sep;6(6):592-606. doi: 10.1055/s-0035-1570749. Epub 2016 Jan 6. Review. PMID: 27556001 Free PMC Article Trends of Posterior Long Segment Fusion with and without Recombinant Human Bone Morphogenetic Protein 2 in Patients with Scoliosis.Ruofeng Y, Cohen JR, Buser Z, Yoon ST, Meisel HJ, Youssef JA, Park JB, Wang JC, Brodke DS. Global Spine J. 2016 Aug;6(5):422-31. doi: 10.1055/s-0035-1564416. Epub 2015 Sep 18. PMID: 27433425 Free PMC Article Sagittal Plane Correction Using the Lateral Transpsoas Approach: A Biomechanical Study on the Effect of Cage Angle and Surgical Technique on Segmental Lordosis.Melikian R, Yoon ST, Kim JY, Park KY, Yoon C, Hutton W. Spine (Phila Pa 1976). 2016 Sep;41(17):E1016-21. doi: 10.1097/BRS.0000000000001562. PMID: 26974836

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The effect of capacitively coupled (CC) electrical stimulation on human disc nucleus pulposus cells and the relationship between CC and BMP-7. Wang Z, Hutton WC, Yoon ST. Eur Spine J. 2017 Jan;26(1):240- 247. doi: 10.1007/s00586-016-4439-y. Epub 2016 Feb 18.PMID: 26892227 Analysis of Knee Joint Line Obliquity after High Tibial Osteotomy. Oh KJ, Ko YB, Bae JH, Yoon ST, Kim JG. J Knee Surg. 2016 Nov;29(8):649-657. Epub 2016 Feb 2. PMID: 26838969 Total Limb Rotation after Unilateral Total Knee Arthroplasty: Side-to-Side Discrepancy.Oh KJ, Yoon ST, Ko YB. J Knee Surg. 2016 Aug;29(6):516-21. doi: 10.1055/s-0035-1566733. Epub 2015 Nov 16.PMID: 26571050 Treatment of Axis Body Fractures: A Systematic Review. Kepler CK, Vaccaro AR, Fleischman AN, Traynelis VC, Patel A, Dekutoski MB, Harrop J, Wood KB, Schroeder GD, Bransford R, Aarabi B, Okonkwo DO, Arnold PM, Fehlings MG, Nassr A, Shaffrey C, Yoon ST, Kwon B. Clin Spine Surg. 2016 Jul 14. [Epub ahead of print] PMID: 26165730 Radiographic Assessment of Guided Growth: The Correlation Between Screw Divergence and Change in Anatomic Alignment. Sweeney KR, Shi WJ, Gottschalk MB, Kappa JE, Bruce RW Jr, Fletcher ND. J Pediatr Orthop. 2017 Jun;37(4):e261-e264. doi: 10.1097/BPO.0000000000000950. PMID: 28141689 The Use of a Transolecranon Pin in the Treatment of Pediatric Flexion-type Supracondylar Humerus Fractures. Green BM, Stone JD, Bruce RW Jr, Fletcher ND. J Pediatr Orthop. 2016 Nov 7. [Epub ahead of print]PMID: 27824796 Use of a Novel Pathway for Early Discharge Was Associated With a 48% Shorter Length of Stay After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis. Fletcher ND, Andras LM, Lazarus DE, Owen RJ, Geddes BJ, Cao J, Skaggs DL, Oswald TS, Bruce RW Jr.J Pediatr Orthop. 2017 Mar;37(2):92-97. doi: 10.1097/BPO.0000000000000601. PMID: 26214327 Radiographic Assessment of Guided Growth: The Correlation Between Screw Divergence and Change in Anatomic Alignment.Sweeney KR, Shi WJ, Gottschalk MB, Kappa JE, Bruce RW Jr, Fletcher ND. J Pediatr Orthop. 2017 Jun;37(4):e261-e264. doi: 10.1097/BPO.0000000000000950.PMID: 28141689 Use of a Novel Pathway for Early Discharge Was Associated With a 48% Shorter Length of Stay After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.Fletcher ND, Andras LM, Lazarus DE, Owen RJ, Geddes BJ, Cao J, Skaggs DL, Oswald TS, Bruce RW Jr. J Pediatr Orthop. 2017 Mar;37(2):92-97. doi: 10.1097/BPO.0000000000000601.PMID: 26214327 Use of Articulating Spacer Technique in Revision Total Knee Arthroplasty Complicated by Sepsis: A Systematic Meta-Analysis.Spivey JC, Guild GN 3rd, Scuderi GR.Orthopedics. 2017 Feb 13:1-9. doi: 10.3928/01477447-20170208-06. [Epub ahead of print] PMID: 28195606 Anthropometric Computed Tomography Reconstruction Identifies Risk Factors for Cortical Perforation in Revision Total Hip Arthroplasty.Guild GN 3rd, Runner RP, Rickels TD, Oldja R, Faizan A.J Arthroplasty. 2016 Nov;31(11):2554-2558. doi: 10.1016/j.arth.2016.04.006. Epub 2016 Apr 13. PMID: 27212394 Efficacy of Hybrid Plasma Scalpel in Reducing Blood Loss and Transfusions in Direct Anterior Total Hip Arthroplasty.Guild GN 3rd, Runner RP, Castilleja GM, Smith MJ, Vu CL. J Arthroplasty. 2017 Feb;32(2):458-462. doi: 10.1016/j.arth.2016.07.038. Epub 2016 Aug 10. PMID: 27659394 Increasing hip and knee flexion during a drop-jump task reduces tibiofemoral shear and compressive forces: implications for ACL injury prevention training.Tsai LC, Ko YA, Hammond KE, Xerogeanes JW, Warren

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GL, Powers CM.J Sports Sci. 2016 Dec 23:1-7. doi: 10.1080/02640414.2016.1271138. [Epub ahead of print]PMID: 28006992 Biomechanical Comparison of Parallel and Crossed Suture Repair for Longitudinal Meniscus Tears. Milchteim C, Branch EA, Maughon T, Hughey J, Anz AW.Orthop J Sports Med. 2016 Apr 8;4(4):2325967116640263. doi: 10.1177/2325967116640263. eCollection 2016 Apr.PMID: 2710420 Computed tomographic analysis of the internal structure of the metacarpals and its implications for hand use, pathology, and surgical intervention.Wong AL, Meals CG, Ruff CB.Anat Sci Int. 2017 Mar 24. doi: 10.1007/s12565-017-0400-3. [Epub ahead of print]PMID: 28341969 Viability of Hand and Wrist Photogoniometry.Meals CG, Saunders RJ, Desale S, Means KR Jr. Hand (N Y). 2017 Apr 1:1558944717702471. doi: 10.1177/1558944717702471. [Epub ahead of print]PMID: 28391753 Suture-Button Reconstruction of the Interosseous Membrane.Meals CG, Forthman CL, Segalman KA. J Wrist Surg. 2016 Aug;5(3):179-83. doi: 10.1055/s-0036-1584547. Epub 2016 Jun 20.PMID: 27468367 Management of adult diaphyseal both-bone forearm fractures.Schulte LM, Meals CG, Neviaser RJ.J Am Acad Orthop Surg. 2014 Jul;22(7):437-46. doi: 10.5435/JAAOS-22-07-437. Review.PMID: 24966250 Effect of perioperative steroids on dysphagia after anterior cervical spine surgery: A systematic review. Adenikinju AS, Halani SH, Rindler RS, Gary MF, Michael KW, Ahmad FU.Int J Spine Surg. 2017 Mar 6;11:9. doi: 10.14444/4009. eCollection 2017.PMID: 28377867 Free PMC Article Laminoplasty versus laminectomy with fusion for the treatment of spondylotic cervical myelopathy: short- term follow-up.Blizzard DJ, Caputo AM, Sheets CZ, Klement MR, Michael KW, Isaacs RE, Brown CR. Eur Spine J. 2017 Jan;26(1):85-93. doi: 10.1007/s00586-016-4746-3. Epub 2016 Aug 23.PMID: 27554354 Percutaneous Image-Guided Cryoablation for the Treatment of Phantom Limb Pain in Amputees: A Pilot Study.Prologo JD, Gilliland CA, Miller M, Harkey P, Knight J, Kies D, Hawkins CM, Corn D, Monson DK, Edalat F, Dariushnia S, Brewster L.J Vasc Interv Radiol. 2017 Jan;28(1):24-34.e4. doi: 10.1016/j.jvir.2016.09.020. Epub 2016 Nov 23. PMID: 27887967 There is No Increased Risk of Adjacent Segment Disease at the Cervico-Thoracic Junction Following an Anterior Cervical Discectomy and Fusion to C7. Louie PK, Presciutti SM, Iantorno SE, Bohl DD, Shah K, Shifflett GD, An HS. Spine J. 2017 Apr 26. pii: S1529-9430(17)30184-5. doi: 10.1016/j.spinee.2017.04.027. [Epub ahead of print]PMID: 28456670 The Treatment and Outcomes of Extraskeletal Osteosarcoma: Institutional Experience and Review of The Literature. Nystrom LM, Reimer NB, Reith JD, Scarborough MT, Gibbs CP Jr.Iowa Orthop J. 2016;36:98- 103. PMID: 27528844 Building better bone: The weaving of biologic and engineering strategies for managing bone loss. Schwartz AM, Schenker ML, Ahn J, Willett NJ. J Orthop Res. 2017 May 3. doi: 10.1002/jor.23592. [Epub ahead of print] PMID: 28467648 -- Seiler JG, Daruwalla JH, Payne SH, Faucher GK. Normal Palmar Anatomy and Variations That Impact Median Nerve Decompression. J Am Acad Orthop Surg. 2017 Sep;25(9):e194-e203. doi: 10.5435/JAAOS-D-16-00038.

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Robins RJ, Daruwalla JH, Gamradt SC, McCarty EC, Dragoo JL, Hancock RE, Guy JA, Cotsonis GA, Xerogeanes JW; ASP Collaborative Group, Tuman JM, Tibone JE, Javernick MA, Yochem EM, Boden SA, Pilato A, Miley JH, Greis PE. Return to Play After Shoulder Instability Surgery in National Collegiate Athletic Association Division I Intercollegiate Football Athletes. Am J Sports Med. 2017 Aug;45(10):2329-2335. doi: 10.1177/0363546517705635. Epub 2017 May 30. Rhee JM, Shi WJ, Cyriac M, Kim JY, Zhou F, Easley KA, Patel A. The P-mJOA: A Patient-derived, Self-reported Outcome Instrument for Evaluating Cervical Myelopathy: Comparison with the mJOA. Clin Spine Surg. 2018 Mar;31(2):E115-E120. doi: 10.1097/BSD.0000000000000591. Vu CCL, Runner RP, Reisman WM, Schenker ML. The Frail Fail: Increased Mortality and Post-Operative Complications in Orthopaedic Trauma Patients. Injury. 2017 Nov;48(11):2443-2450. doi: 10.1016/j.injury.2017.08.026. Epub 2017 Aug 18. Bellamy JL, Runner RP, Vu CCL, Schenker ML, Bradbury TL, Roberson JR. Modified Frailty Index Is an Effective Risk Assessment Tool in Primary Total Hip Arthroplasty. J Arthroplasty. 2017 Oct;32(10):2963-2968. doi: 10.1016/j.arth.2017.04.056. Epub 2017 May 4. Runner RP, Bellamy JL, Vu CCL, Erens GA, Schenker ML, Guild GN 3rd. Modified Frailty Index Is an Effective Risk Assessment Tool in Primary Total Knee Arthroplasty. J Arthroplasty. 2017 Sep;32(9S):S177-S182. doi: 10.1016/j.arth.2017.03.046. Epub 2017 Mar 29. Shau D, Patton R, Patel S, Ward L, Guild G 3rd. Synthetic Mesh Vs. Allograft Extensor Mechanism Reconstruction in Total Knee Arthroplasty - A Systematic Review of the Literature and Meta-Analysis. Knee. 2018 Jan;25(1):2-7. doi: 10.1016/j.knee.2017.12.004. Epub 2018 Jan 8. Segal D, Wilson JM, Staley C, Michael KW. The 5-item Modified Frailty Index is Predictive of 30-day Postoperative Complications in Patients Undergoing Kyphoplasty Vertebral Augmentation. World Neurosurg. 2018 May 2. pii: S1878-8750(18)30892-1. doi: 10.1016/j.wneu.2018.04.172. [Epub ahead of print] Patel NN, Labib SA. The Achilles Tendon in Healthy Subjects: An Anthropometric and Ultrasound Mapping Study. J Foot Ankle Surg. 2018 Mar - Apr;57(2):285-288. doi: 10.1053/j.jfas.2017.10.005. Epub 2017 Dec 21. Grabel ZJ, Armaghani SJ, Vu C, Jain A, Yoon ST. Variations in Treatment of C2 Fractures by Time, Age, and Geographic Region in the United States: An Analysis of 4818 Patients. World Neurosurg. 2018 May;113:e535-e541. doi: 10.1016/j.wneu.2018.02.083. Epub 2018 Feb 21. Grabel ZJ, Hart RA, Clark AJ, Park SH, Shaffrey CI, Scheer JK, Smith JS, Kelly MP, DePasse JM, Gupta MC, Ames CP, Daniels AH. Adult Spinal Deformity Knowledge in Orthopedic Spine Surgeons: Impact of Fellowship Training, Experience, and Practice Characteristics. Spine Deform. 2018 Jan;6(1):60-66. doi: 10.1016/j.jspd.2017.06.003. Stephens BF, Rhee JM, Neustein TM, Arceo R. Laminoplasty Does not Lead to Worsening Axial Neck Pain in the Properly Selected Patient With Cervical Myelopathy: A Comparison With Laminectomy and Fusion. Spine (Phila Pa 1976). 2017 Dec 15;42(24):1844-1850. doi: 10.1097/BRS.0000000000002308. Wise BT, Erens G, Pour AE, Bradbury TL, Roberson JR. Long-Term Results of Extensor Mechanism Reconstruction Using Achilles Tendon Allograft After Total Knee Arthroplasty. Int Orthop. 2018 Mar 7. doi: 10.1007/s00264-018-3848-4. [Epub ahead of print]

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Hinds RM, Capo JT, Rizzo M, Roberson JR, Gottschalk MB. Total Wrist Arthroplasty Versus Wrist Fusion: Utilization and Complication Rates as Reported by ABOS Part II Candidates. Hand (N Y). 2017 Jul;12(4):376-381. doi: 10.1177/1558944716668846. Epub 2016 Sep 12. Tenenbaum S, Bariteau JT, Chechik O, Givon A, Peleg K, Thein R; Israeli Trauma Group. Lower Extremity Fractures in Hospitalized Pediatric Patients Following Road Traffic Accidents. Pediatr Emerg Care. 2018 May 5. doi: 10.1097/PEC.0000000000001504. [Epub ahead of print] Bariteau JT, Kadakia RJ, Traub BC, Viggeswarapu M, Willett NJ. Impact of Vancomycin Treatment on Human Mesenchymal Stromal Cells During Osteogenic Differentiation. Foot Ankle Int. 2018 Apr 1:1071100718766655. doi: 10.1177/1071100718766655. [Epub ahead of print] Boden SA, Boden AL, Mignemi D, Bariteau JT. Liquifying PLDLLA Anchor Fixation in Achilles Reconstruction for Insertional Tendinopathy. Foot Ankle Spec. 2018 Apr;11(2):162-167. doi: 10.1177/1938640017740676. Epub 2017 Nov 14. Tenenbaum S, Weltsch D, Bariteau JT, Givon A, Peleg K, Thein R, Israeli Trauma Group. Orthopaedic Injuries Among Electric Bicycle Users. Injury. 2017 Oct;48(10):2140-2144. doi: 10.1016/j.injury.2017.08.020. Epub 2017 Aug 11. Kadakia RJ, Ahearn BM, Tenenbaum S, Bariteau JT. Costs Associated With Geriatric Ankle Fractures. Foot Ankle Spec. 2017 Feb;10(1):26-30. doi: 10.1177/1938640016666919. Epub 2016 Sep 20. Tsai LC, Ko YA, Hammond KE, Xerogeanes JW, Warren GL, Powers CM. Increasing Hip and Knee Flexion During a Drop-Jump Task Reduces Tibiofemoral Shear and Compressive Forces: Implications for ACL Injury Prevention Training. J Sports Sci. 2017 Dec;35(24):2405-2411. doi: 10.1080/02640414.2016.1271138. Epub 2016 Dec 23. Green BM, Stone JD, Bruce RW Jr, Fletcher ND. The Use of a Transolecranon Pin in the Treatment of Pediatric Flexion-type Supracondylar Humerus Fractures. J Pediatr Orthop. 2017 Sep;37(6):e347-e352. doi: 10.1097/BPO.0000000000000904. Shaw KA, Fletcher ND, Devito DP, Murphy JS. Complications Following Lengthening of Spinal Growing Implants: Is Postoperative Admission Necessary? J Neurosurg Pediatr. 2018 Apr 27:1-6. doi: 10.3171/2018.2.PEDS1827. [Epub ahead of print] Sweeney KR, Shi WJ, Gottschalk MB, Kappa JE, Bruce RW Jr, Fletcher ND. Radiographic Assessment of Guided Growth: The Correlation Between Screw Divergence and Change in Anatomic Alignment. J Pediatr Orthop. 2017 Jun;37(4):e261-e264. doi: 10.1097/BPO.0000000000000950. Labib SA. Editorial Commentary: The Amsterdam Achilles Tendinopathy Endoscopic Treatment: Should We Start Booking Our Patients for Surgery? Arthroscopy. 2018 Jan;34(1):270-271. doi: 10.1016/j.arthro.2017.08.233. Broecker JS, Ethun CG, Monson DK, Lopez-Aguiar AG, Le N, McInnis M, Godette K, Reimer NB, Oskouei SV, Delman KA, Staley CA, Maithel SK, Cardona K. The Oncologic Impact of Postoperative Complications Following Resection of Truncal and Extremity Soft Tissue Sarcomas. Ann Surg Oncol. 2017 Nov;24(12):3574-3586. doi: 10.1245/s10434-017-6034-9. Epub 2017 Sep 11.

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Ogilvie CM, Schwartz AM, Reimer NB. What's New in Musculoskeletal Tumor Surgery. J Bone Joint Surg Am. 2017 Dec 20;99(24):2127-2132. doi: 10.2106/JBJS.17.01072. Aizpuru M, Staley C, Reisman W, Gottschalk MB, Schenker ML. Determinants of Length of Stay After Operative Treatment for Femur Fractures. J Orthop Trauma. 2018 Apr;32(4):161-166. doi: 10.1097/BOT.0000000000001086. Bernstein J, Bernstein JJ, Mehta S, Hume EL, Schenker ML, Ahn J. Defining the Key Parts of a Procedure: Implications for Overlapping Surgery. J Am Acad Orthop Surg. 2018 Feb 15;26(4):142-147. doi: 10.5435/JAAOS-D-17-00381. Vu CCL, Runner RP, Reisman WM, Schenker ML. The Frail Fail: Increased Mortality and Post-Operative Complications in Orthopaedic Trauma Patients. Injury. 2017 Nov;48(11):2443-2450. doi: 10.1016/j.injury.2017.08.026. Epub 2017 Aug 18. Fitzgerald CA, Moore TJ Jr, Morse BC, Subramanian A, Dente CJ, Patel DC, Reisman WM, Schenker ML, Gelbard RB. The Role of Diverting Colostomy in Traumatic Blunt Open Pelvic Fractures. Am Surg. 2017 Aug 1;83(8):280-282. Schwartz AM, Schenker ML, Ahn J, Willett NJ. Building Better Bone: The Weaving of Biologic and Engineering Strategies for Managing Bone Loss. J Orthop Res. 2017 Sep;35(9):1855-1864. doi: 10.1002/jor.23592. Epub 2017 May 23. Review. Daly CA, Boden AL, Hutton WC, Gottschalk MB. Biomechanical Strength of Retrograde Fixation in Proximal Third Scaphoid Fractures. Hand (N Y). 2018 Apr 1:1558944718769385. doi: 10.1177/1558944718769385. [Epub ahead of print] Premkumar A, Godfrey W, Gottschalk MB, Boden SD. Red Flags for Low Back Pain Are Not Always Really Red: A Prospective Evaluation of the Clinical Utility of Commonly Used Screening Questions for Low Back Pain. J Bone Joint Surg Am. 2018 Mar 7;100(5):368-374. doi: 10.2106/JBJS.17.00134. Boden LM, Boden SA, Premkumar A, Gottschalk MB, Boden SD. Predicting Likelihood of Surgery Prior to First Visit in Patients with Back and Lower Extremity Symptoms: A Simple Mathematical Model Based On Over 8000 Patients. Spine (Phila Pa 1976). 2018 Feb 9. doi: 10.1097/BRS.0000000000002603. [Epub ahead of print] Muppavarapu RC, Tsytsikova L, Gottschalk MB, Dalwadi PP, Cassidy C. Functional Outcomes of 24-Hour Thumb Immobilization in Healthy Volunteers: Prospective Comparative Study. J Wrist Surg. 2017 Aug;6(3):201-205. doi: 10.1055/s-0037-1598025. Epub 2017 Jan 23. Tetreault LA, Rhee J, Prather H, Kwon BK, Wilson JR, Martin AR, Andersson IB, Dembek AH, Pagarigan KT, Dettori JR, Fehlings MG. Change in Function, Pain, and Quality of Life Following Structured Nonoperative Treatment in Patients With Degenerative Cervical Myelopathy: A Systematic Review. Global Spine J. 2017 Sep;7(3 Suppl):42S-52S. doi: 10.1177/2192568217700397. Epub 2017 Sep 5. Review. Rhee J, Tetreault LA, Chapman JR, Wilson JR, Smith JS, Martin AR, Dettori JR, Fehlings MG. Nonoperative Versus Operative Management for the Treatment Degenerative Cervical Myelopathy: An Updated Systematic Review. Global Spine J. 2017 Sep;7(3 Suppl):35S-41S. doi: 10.1177/2192568217703083. Epub 2017 Sep 5. Review.

2018 Kelly Day Journal

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Fehlings MG, Tetreault LA, Riew KD, Middleton JW, Aarabi B, Arnold PM, Brodke DS, Burns AS, Carette S, Chen R, Chiba K, Dettori JR, Furlan JC, Harrop JS, Holly LT, Kalsi-Ryan S, Kotter M, Kwon BK, Martin AR, Milligan J, Nakashima H, Nagoshi N, Rhee J, Singh A, Skelly AC, Sodhi S, Wilson JR, Yee A, Wang JC. A Clinical Practice Guideline for the Management of Patients With Degenerative Cervical Myelopathy: Recommendations for Patients With Mild, Moderate, and Severe Disease and Nonmyelopathic Patients With Evidence of Cord Compression. Global Spine J. 2017 Sep;7(3 Suppl):70S-83S. doi: 10.1177/2192568217701914. Epub 2017 Sep 5. Walsh WR, Pelletier MH, Christou C, He J, Vizesi F, Boden SD. The In Vivo Response to a Novel Ti Coating Compared with Polyether Ether Ketone: Evaluation of the Periphery and Inner Surfaces of an Implant. Spine J. 2018 Feb 26. pii: S1529-9430(18)30075-5. doi: 10.1016/j.spinee.2018.02.017. [Epub ahead of print] Louie PK, Presciutti SM, Iantorno SE, Bohl DD, Shah K, Shifflett GD, An HS. There is No Increased Risk of Adjacent Segment Disease at the Cervicothoracic Junction Following an Anterior Cervical Discectomy and Fusion To C7. Spine J. 2017 Sep;17(9):1264-1271. doi: 10.1016/j.spinee.2017.04.027. Epub 2017 Apr 26. Boden AL, Daly CA, Dalwadi PP, Boden SA, Hutton WC, Muppavarapu RC, Gottschalk MB. Biomechanical Evaluation of Standard Versus Extended Proximal Fixation Olecranon Plates for Fixation of Olecranon Fractures. Hand (N Y). 2018 Jan 1:1558944717753206. doi: 10.1177/1558944717753206. [Epub ahead of print] Gill TJ, Safran M, Mandelbaum B, Huber B, Gambardella R, Xerogeanes J. A Prospective, Blinded, Multicenter Clinical Trial to Compare the Efficacy, Accuracy, and Safety of In-Office Diagnostic Arthroscopy With Magnetic Resonance Imaging and Surgical Diagnostic Arthroscopy. Arthroscopy. 2018 May 24. pii: S0749-8063(18)30229-9. doi: 10.1016/j.arthro.2018.03.010. [Epub ahead of print] Sheean AJ, Musahl V, Slone HS, Xerogeanes JW, Milinkovic D, Fink C, Hoser C; International Quadriceps Tendon Interest Group. Quadriceps Tendon Autograft for Arthroscopic Knee Ligament Reconstruction: Use it Now, Use it Often. Br J Sports Med. 2018 Jun;52(11):698-701. doi: 10.1136/bjsports-2017-098769. Epub 2018 Apr 28. Review. Robins RJ, Daruwalla JH, Gamradt SC, McCarty EC, Dragoo JL, Hancock RE, Guy JA, Cotsonis GA, Xerogeanes JW; ASP Collaborative Group, Tuman JM, Tibone JE, Javernick MA, Yochem EM, Boden SA, Pilato A, Miley JH, Greis PE. Return to Play After Shoulder Instability Surgery in National Collegiate Athletic Association Division I Intercollegiate Football Athletes. Am J Sports Med. 2017 Aug;45(10):2329-2335. doi: 10.1177/0363546517705635. Epub 2017 May 30. Xerogeanes J, Ghasem A, Todd D. Height, Weight, and Age Predict Quadriceps Tendon Length and Thickness in Skeletally Immature Patients: Response. Am J Sports Med. 2017 Jul;45(9):NP27. doi: 10.1177/0363546517717700. Patton RS, Runner RP, Lyons RJ, Bradbury TL. Clinical Outcomes of Patients With Lateral Femoral Cutaneous Nerve Injury After Direct Anterior Total Hip Arthroplasty. J Arthroplasty. 2018 Apr 24. pii: S0883-5403(18)30393-0. doi: 10.1016/j.arth.2018.04.032. [Epub ahead of print]