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Year: 2017

Closed reduction and fluoroscopic assisted percutaneous pinning of 42physeal fractures in 37 dogs and 4 cats

Boekhout-Ta, Christina L ; Kim, Stanley E ; Corss, Alan R ; Pozzi, Antonio ; Evans, Richard

Abstract: OBJECTIVE: To report complications and clinical outcome of dogs and cats that underwentfluoroscopic-assisted percutaneous pinning (FAPP) of physeal fractures. STUDY DESIGN: Retrospec-tive study. ANIMALS: Client-owned dogs (n = 37) and cats (n = 4). MATERIALS AND METHODS:Records (August 2007-August 2014) of physeal fractures treated with FAPP in 3 hospitals were evaluated.Data collected included signalment, fracture characteristics (etiology, location, duration, Salter-Harrisclassification, preoperative and postoperative displacement), surgical information (implant size, surgicalduration), and outcome assessment information (functional outcome, radiographic outcome, and com-plications). RESULTS: The majority of animals (92%) were classified as full functional outcome. Nosignificant predictors of functional outcome were identified. The overall complication rate was 15% (n= 6). Elective pin removal rate was 41% (n = 17). Goniometry and limb circumference measurementsof the affected and contralateral limbs were not significantly different in dogs for which measurementswere obtained. Seventeen of 18 animals (16 dogs, 2 cats) measured had bone length changes on follow-upradiographs. CONCLUSION: FAPP is associated with an excellent functional outcome in a narrow se-lection of fracture configurations, specifically those with minimal displacement and for which anatomicalalignment can be achieved with closed reduction.

DOI: https://doi.org/10.1111/vsu.12582

Posted at the Zurich Open Repository and Archive, University of ZurichZORA URL: https://doi.org/10.5167/uzh-132274Journal ArticleAccepted Version

Originally published at:Boekhout-Ta, Christina L; Kim, Stanley E; Corss, Alan R; Pozzi, Antonio; Evans, Richard (2017). Closedreduction and fluoroscopic assisted percutaneous pinning of 42 physeal fractures in 37 dogs and 4 cats.Veterinary Surgery, 46(1):103-110.DOI: https://doi.org/10.1111/vsu.12582

Title Page 1

Running Head: FAPP of Physeal Fractures 2

Title: Closed Reduction and Fluoroscopic Assisted Percutaneous Pinning of 42 Physeal 3

Fractures in 37 dogs and 4 cats 4

Authors: 5

Christina L Boekhout-Ta1 DVM, DACVS-SA 6

Utah Veterinary Center, Salt Lake City, UT 7

8

Stanley E. Kim2 BVSc, MS, DACVS 9

University of Florida, Gainesville, FL 10

11

Alan R. Cross3 DVM, DACVS 12

Georgia Veterinary Specialists, Atlanta, GA 13

14

Antonio Pozzi4 DVM, MS, DACVS, DECVS, DASVSMR 15

University of Zurich, Zurich, Switzerland 16

17

Richard Evans5 PhD 18

University of Missouri, Columbia, MO 19

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No financial support was provided and this study was internally funded. An earlier 21

version of this study was presented as an abstract at the 4th

World Veterinary Orthopaedic 22

Congress & 41st Veterinary Orthopedic Society Conference in March 1-8, 2014 at 23

Breckenridge, CO. The abstract was titled “Closed Reduction and Fluoroscopic assisted 24

percutaneous pinning of physeal fractures in 27 dogs and 4 cats”. 25

Corresponding Author: 26

Christina L. Boekhout-Ta DVM, DACVS-SA 27

Utah Veterinary Center 28

308 W. 7200 S. Midvale, UT, 84047 29

boekhcl@gmail.com 30

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Abstract 45

Objective: To report complications and clinical outcome of dogs and cats that underwent 46

fluoroscopic assisted percutaneous pinning (FAPP) of physeal fractures. 47

Study Design: Retrospective 48

Animals: Client-owned dogs (n=37) and cats (n=4). 49

Materials and Methods: Records (August 2007- August 2014) of physeal fractures 50

treated with FAPP in three hospitals were evaluated. Data collected included signalment, 51

fracture characteristics (etiology, location, duration, Salter Harris classification, pre- and 52

post-operative displacement), surgical information (implant size, surgical duration), and 53

outcome assessment information (functional outcome, radiographic outcome, and 54

complications). 55

Results: The majority of patients (92%) were classified as full functional outcome. No 56

significant predictors of functional outcome were identified. The overall complication 57

rate was 15% (n=6). Elective pin removal rate was 40% (n=17). Goniometry and limb 58

circumference measurements of the affected and contralateral limbs were not 59

significantly different in patients which measurements were obtained. Seventeen of 18 60

patients measured had bone length changes on follow-up radiographs. 61

Conclusions: FAPP is associated with an excellent functional outcome in a narrow 62

selection of fractures. 63

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Introduction 68

Physeal fractures are common, constituting up to 30 percent of appendicular 69

fractures in immature dogs.1 Salter-Harris (SH) types I and II are the most common 70

representing 77 percent of physeal fractures, however sparse reports on surgical outcome 71

measures exist in veterinary medicine.1 Traditionally, the majority of physeal fractures in 72

dogs and cats have been repaired with open reduction and internal fixation (ORIF). 73

Kirshner wire fixation is commonly used, with different configurations such as parallel, 74

cross, or dynamic pinning.2,3

Clinical outcome following ORIF has been reported to be 75

good to excellent,4-7

although lack of physeal function post-operatively can lead to 76

growth abnormalities in some cases.2 77

Fluoroscopic assisted percutaneous pinning (FAPP), a minimally invasive fracture 78

repair technique, consists in closed reduction and internal fixation by Kirschner wires 79

inserted through small skin incisions under fluoroscopic guidance.8 FAPP is commonly 80

performed in children, with success rates between 68% and 100%, excellent patient 81

satisfaction compared to ORIF, and infrequent loss of reduction compared to external 82

coaptation .9,10

The advantages of FAPP over ORIF and external coaptation in children 83

are most apparent in the immediate post-operative period with all techniques having 84

similar long-term outcomes.9,10

Long-term complications following physeal fracture 85

repair in children have been shown to be influenced by age, affected physis, time between 86

injury and surgery, trauma etiology, Salter-Harris classification, and fracture 87

displacement.11

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89

The reported outcome of minimally invasive fracture repair in dogs is excellent.4,

90

12-14 Short time to healing and low risk of complications have been associated with 91

minimally invasive plating of diaphyseal radial and tibial fractures.13,14

In keeping with 92

the principles of biologic fracture fixation, alternatives to traditional ORIF of physeal 93

fractures, such as FAPP, should be considered in attempt to improve clinical outcomes. 94

Potential advantages of FAPP include faster patient recovery, decreased pain, decreased 95

infection, and limited iatrogenic trauma to the physis, soft tissues, and surrounding blood 96

supply. Potential disadvantages of minimally invasive fracture repair include less 97

accurate fracture reduction, increased risk of malalignment and increased surgical time. 98

Veterinary studies evaluating outcome following FAPP are limited. A single 99

veterinary study reported a good outcome with closed reduction and blind percutaneous 100

pinning of femoral and tibial fractures, seven of which were physeal fractures.15

The 101

reported advantages of fluoroscopy for pin placement for spinal stabilization in dogs 102

include decreased operative trauma, post-operative morbidity, and improved accuracy 103

and safety .12

Cook et al, reported good outcomes following fluoroscopic assisted 104

percutaneous pin and screw placement for lateral humeral condyle fracture repair in 105

immature and adult dogs.4 Recently the technique of FAPP for capital physeal fractures 106

and FAPP for physeal fractures was described, however, clinical outcome was not 107

reported.8,16

108

Our objectives were to retrospectively report complications and clinical outcome 109

of dogs and cats that underwent FAPP of physeal fractures. We hypothesized FAPP is a 110

safe and effective technique to facilitate healing of physeal fractures. Safety was defined 111

based on the morbidity associated with the procedure and efficacy was defined as the 112

ability of the technique to return the animal to pre-operative function. 113

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Materials and Methods 135

Study Population 136

Medical records (August 2007- August 2014) of dogs and cats with FAPP of 137

physeal fractures without conversion to an open approach in three veterinary hospitals 138

(Animal Specialty and Emergency Center, University of Florida, Georgia Veterinary 139

Specialists) were identified retrospectively. Cases were excluded from the study due to 140

conversion to an open approach. Pre- and post-operative radiographs and complete 141

surgical reports were required for study inclusion. Data collected included signalment, 142

fracture characteristics (etiology, location, duration, SH classification, pre- and post-143

operative displacement), surgical information (implant size, surgical duration), and 144

outcome assessment information (functional outcome, radiographic outcome, and 145

complications). 146

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Surgical Procedure 148

The technique utilized by the authors was as previously described by Kim et al.8 149

Briefly, manual traction and counter pressure were applied to facilitate closed reduction. 150

Reduction was confirmed with intra-operative fluoroscopy prior to implant placement 151

(Fig 1). Internal fixation with small diameter smooth bone pins through small skin 152

incisions or directly percutaneously was performed in the same manner as pin placement 153

for open physeal fracture repair (e.g. cross pins, parallel pins) depending on the affected 154

physis. Internal fixation was evaluated intra-operatively with fluoroscopy (Fig 1). 155

Surgical duration was defined as the start of closed reduction to removal of the drapes. 156

Intra-operative differences between surgical facilities included the mobile fluoroscopic 157

unit, surgeon experience level, and treatment of the cut pin ends. Surgeons included 158

residents and boarded surgeons. Cut pin ends were countersunk, bent, left long but 159

subcutaneous, or cut as short as possible. Mobile fluoroscopic units included Siremobil 160

Compact Fluoroscope (Siemens, Iselin, NJ), Pulsera (Philips, Andover, MA), and Philips 161

BV3000 (Philips, Andover, MA). 162

Distal tibial and radial fractures were protected with external coaptation (lateral 163

and caudal splints respectively) until clinical union of the physeal fracture. Clinical 164

union was defined as palpable stability of the fracture repair. Passive range of motion 165

and cold compression was initiated postoperatively in fractures at the level of the 166

shoulder, hip, and stifle. Non-steroidal anti-inflammatory drugs were prescribed for two 167

weeks postoperatively. Activity restriction including cage rest and short controlled walks 168

were recommended. Radiographs were recommended every two weeks to monitor 169

fracture healing. 170

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Functional Assessment 172

Post-operative rechecks were variable between 1 and 6 weeks until clinical union was 173

achieved. Patients were requested to return for an outcome evaluation following clinical 174

union. Full outcome evaluation included a subjective lameness examination, validated 175

owner questionnaire,17

objective measurements (goniometry and limb circumference) and 176

radiographs of the affected and contralateral bone. Lameness was graded on a 5 point 177

scale, where 0 is normal, grade 1 is mild subtle lameness with partial weight bearing, 178

grade 2 is obvious lameness with partial weight bearing, grade 3 is obvious lameness 179

with intermittent weigh bearing, and grade 4 is full non-weight bearing lameness. 180

Goniometry included flexion and extension of the joint adjacent to the fractured physis 181

and the contralateral joint. Goniometry was performed as previously described.18

182

Briefly, the center of the goniometer was placed at the joint and the arms of the 183

goniometer along the long axis of the adjacent diaphysis. Limb circumference was only 184

obtained on the hindlimb with a tape measure and was measured at 50% of the length of 185

the femur on the affected and contralateral limb. For those patients that did not return for 186

the full outcome evaluation, owners were contacted and asked to complete the 187

questionnaire. If the owner was unable, functional outcome was determined by phone 188

interview or by the attending clinician at the last recheck examination. 189

Functional outcome assessment was defined as previously described by Cook et 190

al.19

Functional outcome was classified as full, acceptable, or unacceptable. Full 191

function was defined as restoration to pre-injury status. Acceptable function was 192

restoration to pre-injury status that was limited in level, duration, or required medication 193

to achieve. Unacceptable function applied to all patients who did not exhibit full or 194

acceptable function. Complications were classified as catastrophic, major, or minor, 195

again as defined by Cook et al.19

Catastrophic complications were those that caused 196

permanent unacceptable function, directly related to death or euthanasia. Major 197

complications were those that required additional medical or surgical intervention beyond 198

the current standard of care. Some surgeons performed elective pin removal; others 199

performed removal if complications were associated with the pin. Minor complications 200

were those that resolved without additional treatment. All complications and subsequent 201

treatments were recorded. 202

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Radiographic Assessment 204

Orthogonal radiographs of the fractured bone were obtained pre- and post-205

operatively and at variably scheduled rechecks. Radiographs of the affected and 206

contralateral bone were obtained using a 10 centimeter calibration marker during the 207

study-related follow-up evaluations. Radiographic assessment included pre- and post-208

operative displacement grading, fracture healing, and measurement of bone length 209

discrepancy between affected and contralateral limbs. 210

Pre-operative radiographs were evaluated for physis affected, Salter Harris (SH) 211

classification, and displacement. Pre-operative fracture displacement was graded as 212

previously described by Arkader et al11

(Fig. 2). Grade 1 was less than 1/3 of the bone 213

width. Grade 2 was 1/3 to 2/3 the bone width. Grade 3 was greater than 2/3 the bone 214

width. 215

Post-operative fracture reduction was graded based on the presence of a 216

metaphyseal-physeal step. This grading system was based on a scoring system previously 217

described by Cook4. Grade 0 was anatomical reduction. Grade 1 was minimal 218

malreduction (<1mm). Grade 2 was moderate malreduction (1-3mm). Grade 3 was 219

severe malreduction (>3mm).Radiographic fracture healing was assessed by radiographic 220

signs (bridging bone seen on both lateral and craniocaudal radiographic projections or 221

loss of physeal lucency), however since the study was retrospective, time to bony union 222

could not be accurately determined due to varied recheck protocols. Complications of 223

bony healing were noted. 224

Measurements performed on orthogonal radiographs from identical points on the 225

affected and contralateral bones were obtained to evaluate bone length discrepancies. 226

Only radiographs with a 10 centimeter calibration marker and with identical positioning 227

between the affected and contralateral limb on radiographic review were used to measure 228

bone length. 229

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Statistical Analysis 231

First, data summaries (means, medians, standard deviations and interquartile 232

ranges) and graphs were used to inspect the data for missing or spurious values and to 233

assess the shape of the variable’s distributions. Next, three types of analyses were used to 234

analyze the data, depending on the kind and distribution of the variable. Correlated data 235

(e.g., affected and contralateral bone lengths) were analyzed with paired t-tests. 236

Relationships between binary (e.g., implant removal) and continuous variables (e.g., pin 237

size) were analyzed with nominal logistic regression with ward chi-square tests for the 238

parameters. Relationships between discrete data in the form of contingency tables were 239

analyzed with chi-square tests or Fisher’s exact tests. Statistical significance was set at 240

P<.05. JMP 11.2.0 (SAS Institute, Cary, NC) used for statistical analysis. 241

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Results 250

Study Population 251

Medical records of 37 dogs and 4 cats with 42 physeal fractures were reviewed. 252

One dog had bilateral tibial fractures. No cases were excluded from the study due to 253

conversion to an open approach. There were 27 males (12 castrated, 15 intact) and 14 254

females (9 spayed, 5 intact). Mean weight was 10.4kg (median 8.8 kg; range, 1.7-255

39.6kg). Mean age was 6.9 months (median 6 months; range, 3-18 months). 256

Radiographs revealed open physes, therefore the patient was included in analysis. 257

Fracture etiology included hit by car (8), fall/drop (16), other (4), unknown (13). 258

Fractured physes included proximal tibia (20), distal femur (8), distal tibia (7), distal 259

radius (3), proximal humerus (3), and capital physis (1). Proximal tibial fractures 260

included proximal tibial physis (13), apophyseal avulsions (1), and a combination of both 261

(6). Mean duration of pre-operative fracture duration was 2 days (median 2 days; range 262

0-8 days). All fractures were SH type I (17) or type II (25). Pre-operative radiographic 263

displacement included grade 1 (26), grade 2(8), and grade 3 (8). 264

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Surgical findings 266

The majority of fractures were treated with crossed pins (n=32, 76%) with the 267

remainder treated with parallel pins (n=10, 24%) (Fig. 3). Pin number ranged from 2 to 6 268

(median 2; mean 2.7). Implant sizes ranged from 0.9-2.4 mm (median 1.1 mm; mean 1.3 269

mm) diameter. Pin ends were bent (9), cut short (6), or left long (27). Surgical duration 270

was reported in 38 patients with a mean of 42 min (median, 30 min; range, 4-119 271

minutes). 272

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Outcome assessment 274

Eleven animals returned for the full outcome assessment (contralateral 275

radiographs, goniometry, thigh circumference measurements, validated questionnaire). 276

The other animals had variable follow-up (Table 1). Mean follow-up duration was 16 277

months (median, 6.3 months; range 25 days-5.7 years). Thirty-seven patients had a 278

reported follow-up evaluation performed by a clinician. Four animals had no follow-up 279

evaluation performed or reported. Thirty-four of the 37 animals had a reported full 280

functional outcome (92%). Three animals had an acceptable outcome (8%). Nineteen 281

animals’ functional outcome was reported by the owner in the questionnaire. Of the 19 282

reported, 17 animals had a full functional outcome, two had an acceptable outcome. The 283

questionnaire results matched with the clinical evaluations. Thirteen animals had 284

goniometry performed. Decreased range of motion (ROM) was noted in 5 of the 13 285

(median 5 degrees; mean 5 degrees; range 2-10). One dog had increased ROM by 5 286

degrees in flexion and extension. Four animals had no difference in goniometry 287

measurements. Goniometry measurements of the affected and contralateral limbs were 288

not significantly different (n=13; P=.022). Twelve animals had limb circumference 289

measurements. Decreased limb circumference of the affected limb was reported in six 290

dogs (median 0.75 cm; mean 2.2 cm; range 0.3-9). One dog had an increase of 1 cm in 291

the affected limb. Five animals had no difference in limb circumference. Limb 292

circumference measurements of the affected and contralateral limbs were not 293

significantly different (n=12; P=.024). 294

Radiographic union was achieved in all cases for which radiographic follow-up 295

was available (n=34). There were no radiographic healing complications. Based on the 296

inconsistent time for radiographic evaluations it was not possible to determine the exact 297

healing time. However, all fractures healed in less than 12 weeks. Eighteen animals 298

returned for follow-up comparison radiographs of the affected and contralateral limbs. 299

Fourteen (78%) had shortening of the affected bone (Fig. 3) and three (17%) had 300

lengthening of the affected bone; those counts are statistically different (P=.006). One 301

(5%) had no change in affected bone length. Bones were shortened or lengthened an 302

average of 5.7% and 1.9%. respectively. Of those with comparison radiographs, 15 had a 303

full functional outcome and 3 had an acceptable outcome. Post-operative fracture 304

displacement included grade 0 (18), grade 1 (14), grade 2 (7), and grade 3 (3). There 305

were no radiographic or clinical outcome measures that were significantly associated 306

with functional outcome. 307

The overall complication rate was 15% (n=6). Major complications (n=5; 12%) 308

included incisional infection that resolved with antimicrobials (n=1), pin irritation with 309

subsequent removal (n=1), septic arthritis (n=1), and pin migration that required 310

subsequent replacement (n=2). A single minor complication was reported in a dog with a 311

broken pin noted on follow-up radiographs (n=1; 2%). Elective pin removal was 312

performed in 41% (n=17) of cases. Pin end management did not significantly influence 313

outcome and was not a predictor for pin removal on statistical analysis. 314

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Discussion 318

In the present study of 37 dogs and 4 cats undergoing FAPP of physeal fractures 319

there was an overall complication rate of 15%. Our clinical observations revealed full 320

functional outcome in the majority of dogs (92%) and no significant difference between 321

objective measurements (goniometry, limb circumference) of the affected and 322

contralateral limb. Although most complications were classified as major, they were not 323

life-threatening, and easily addressed without significant patient morbidity. 324

One of the important findings of the study was the high rate of elective implant 325

removal. The pin ends were managed in different ways, including cut short and 326

countersunk, bent or left long to facilitate removal. However, there was no statistically 327

significant effect of pin end management on implant removal. We are not aware of an 328

established standard of care recommendation regarding elective pin removal following 329

physeal fracture repair in veterinary medicine. We propose to establish a standard of care 330

that includes planification for elective pin removal following physeal fracture repair in 331

small animal surgery. 332

The pin removal rate for ORIF of physeal fractures is not currently known. Three 333

previous studies on fracture pinning have included a subset of patients with physeal 334

fractures. In 1989, a study evaluating blind pinning of the tibia and femur reported a pin 335

removal rate of 71% in seven physeal fractures .15

In 2004, Fisher et al reported a pin 336

removal rate of 56% in 16 feline capital physeal fractures.5 Saglam and Kaya reported 337

that no pin removals were performed in 7 dogs undergoing ORIF of proximal tibial 338

fractures.6 Arguments have been made in both human and veterinary medicine 339

supporting elective pin removal to prevent premature closure of the physis.2,16,20

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Most animals included in this study were rechecked by a clinician and had an 341

excellent outcome, based on the restoration to pre-injury status. Despite our results we 342

cannot make valid comparisons between FAPP and ORIF as we did not include an ORIF 343

cohort. In human medicine, comparable long-term outcomes have been reported between 344

open pinning and percutaneous pinning; however, significant improvement in patient 345

satisfaction was reported in children undergoing percutaneous pinning compared to open 346

pinning.9 Patient satisfaction is difficult to quantify in animal patients, however, we 347

suspect there is decreased post-operative morbidity and greater owner satisfaction with 348

FAPP based on the experiences of the surgeons involved with these cases. 349

We found a significant difference in length between the affected and contralateral 350

bones in the 18 patients that returned for radiographic comparison, however, it never 351

exceeded 6%. Length change did not significantly influence functional outcome. In the 352

14 patients that had shortening of the affected bone, we presume this finding was 353

secondary to premature closure of the involved physis. This finding is unexpected 354

because most fractures were SH type 1 or 2, which should carry the best prognosis.20

355

Interestingly, three patients had increased length of the affected bone. A single 356

veterinary report describes lengthening of the humeral diaphysis following physeal 357

fracture repair.21

It was speculated that lengthening could be secondary to decreased 358

stress on the fractured physis or possibly over stimulation of the physis. Future studies 359

evaluating sequential radiographic monitoring of the physis would be necessary to 360

support these speculations in our patient population. 361

Limitations of this study include those inherent to retrospective, multi-center 362

studies: lack of an ORIF cohort; variations in surgeon skill and technique; modifications 363

of and improvements in the technique during the course of the study; and variable case 364

follow-up. Some intra-operative data variability was likely attributed to surgeon 365

variability and training. Surgeons included both surgical residents and board certified 366

surgeons. Given FAPP is a newer technique; several surgeons were initially unfamiliar 367

with the percutaneous pinning technique resulting in longer operative times and possibly 368

poorer post-operative results. Surgeon was not included as a variable in our data 369

analysis. As a retrospective, multi-center study, we expected a large amount of case 370

variability in the follow-up data. Case numbers declined as more complete follow-up 371

data was obtained. 372

Most fractures included in the study were minimally displaced, suggesting that 373

preoperative fracture displacement played an important role in the selection of FAPP 374

versus ORIF. In children the distance of fracture displacement is used as selection criteria 375

for choosing between closed reduction and open reduction.22

In a recent study in 286 376

children, open reduction was selected in patients with more than 2 mm of fracture 377

displacement, even after closed reduction.22

Based on our experience, we would 378

recommend FAPP for fractures with minimal displacement. In addition, we would 379

consider FAPP only if anatomical alignment could be achieved with closed reduction. 380

Post-operative fracture displacement did not influence patient outcome. In human 381

literature, the presence of displacement has been associated with increased complications 382

in children with distal femoral physeal fractures. Additionally, increased displacement 383

has been correlated with an increased likelihood of complications.11

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Based on the overall results of this study, FAPP is a safe procedure associated 385

with a high elective pin removal rate and an excellent final functional outcome. 386

Acknowledgment 387

We acknowledge Dr. Scott A. Christopher for his assistance with data accumulation. 388

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Disclosure 410

The authors report no financial or other conflicts related to this report. 411

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in dogs. Turk J Vet Anim Sci 2004;28:799-805 448

7. Clements DN, Gemmill T, Corr SA, et al: Fracture of the proximal tibial 449

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10. Miller BS, Taylor B, Widmann RF, et al: Cast immobilization versus 457

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Pediatr Orthop 2005;25:490-494 459

11. Arkader A, Warner WC, Horn BD, et al: Predicting the outcome of physeal 460

fractures of the distal femur. J Pediatr Orthop 2007;27:703-708 461

12. Wheeler JL, Lewis DD, Cross AR, et al: Closed fluoroscopic-assisted spinal arch 462

external skeletal fixation for the stabilization of vertebral column injuries in five 463

dogs. Vet Surg 2007;36:442-448 464

13. Pozzi A, Hudson CC, Gauthier C, et al: A retrospective comparison of minimally 465

invasive plate osteosynthesis and open reduction and internal fixation for radius-466

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Saunders, 2012,pp 882-883 475

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21. Lefeebvre JB, Robertson TR, Baines SJ, et al: Assessment of humeral length in 486

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children. Orthopedics 2015;38:189-195 490

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Figure Legend 499

Figure 1: Intraoperative fluoroscopic images (A, B), postoperative (C) and 4-week 500

recheck (D) radiographs of a 7 month-old mixed breed dog presented with a grade 1 501

(displacement grade 1=minimally displaced, grade 2=mildly displaced, grade 3=severely 502

displaced), proximal tibial physeal fracture (Salter Harris type 1). The fracture was 503

reduced by extending the stifle and applying traction using bone reduction forceps (A). A 504

2 mm K-wire was inserted through the tibial tuberosity to stabilize the fracture. Then, 505

additional 2 mm K-wires were inserted medially and laterally (B). 506

507

Figure 2: Representative radiographs of three animals with grade 1 (<1/3 bone width 508

displacement), grade 2 (1/3 to 2/3 bone width displacement) and grade 3 (>2/3 bone 509

width displacement). 510

511

Fig. 3: Preoperative (A, B), postoperative (C, D) and 1 year recheck examination (E, F) 512

radiographs of a 8 month-old Jack Russell Terrier presented with a grade 1 (displacement 513

grade 1=minimally displaced, grade 2=mildly displaced, grade 3=severely displaced), 514

distal femoral physeal fracture (Salter Harris type 2). The fracture was reduced using 515

manual manipulation and 1.5 mm K-wires were inserted percutaneous distal-to-proximal. 516

No growth abnormalities were detected at 1-year recheck examination (E, F). 517

518

Fig. 4: Preoperative (A, B), postoperative (C, D) and 2-year recheck examination (E, F) 519

radiographs of a 9 month-old mixed breed dog presented with a grade 3 (displacement 520

grade 1=minimally displaced, grade 2=mildly displaced, grade 3=severely displaced), 521

proximal humeral physeal fracture. The fracture was reduced using manual manipulation 522

and 1 mm K-wires were inserted percutaneous proximo-to-distal. Mild rotational 523

malalignment was noted in the postoperative radiographs (C, D). Shortening was detected 524

at 2 year recheck examination (E, F), but excellent function was reported by the owner. 525

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Tables 545

Table 1 Variability in Patient Follow-up 546

Description of

Follow-up Number of patients

Full (E, CR, G, Q) 11

E 1

E, P 4

E, R 11*

E, CR 5

E, R, P 2

E, CR, Q 1

E, CR, G 1

E, R, Q 3

No follow-up 2

E, exam; CR, contralateral radiographs; G, goniometry; Q, validated questionnaire; P, 547

phone; R, follow-up radiographs 548

* Includes dog with bilateral procedures 549