5SProceedings of the NASS 23rd Annual Meeting / The Spine Journal 8 (2008) 1S–191S

9. Oxiplex Reduces the Incidence of Back Pain, Leg Pain and

Associated Symptoms Six Months Following Single-Level Lumbar

Laminectomy for Removal of a Herniated Disc

Jeffrey Wang, MD1, Paul Arnold, MD2; 1University of California, Los

Angeles, Santa Monica, CA, USA; 2University of Kansas, Kansas City, KS,

USA

BACKGROUND CONTEXT: Oxiplex gel (carboxymethylcellulose,

polyethylene oxide and calcium) was developed to coat and protect nerve

roots for reduction of pain and symptoms following lumbar disc surgery.

PURPOSE: To evaluate the safety and effectiveness of Oxiplex gel

for reduction of pain and associated symptoms following lumbar disc

surgery.

STUDY DESIGN/ SETTING: The study was a randomized, third-party

blinded, multicenter, pivotal clinical trial to evaluate the safety and effec-

tiveness of Oxiplex gel to reduce postoperative back and leg pain as well as

related symptoms following surgery for removal of a herniated lumber disc

at L4-L5 or L5-S1.

PATIENT SAMPLE: Patients undergoing single-level lumbar laminec-

tomy or laminotomy, and a discectomy randomized to receive either sur-

gery plus Oxiplex (n5177) or surgery alone (n5175).

OUTCOME MEASURES: At baseline and following surgery at 1, 3,

and 6 months patients were evaluated using 1) quality of life measures

(Lumbar Spine Outcomes Questionnaire: LSOQ, BenDebba et al., Spine

J. 7:118–132), and 2) clinical evaluations were performed at 1 and 6

months.

METHODS: Patients undergoing single-level lumbar laminectomy, lami-

notomy, or discectomy were ineroperatively randomized to receive either

surgery plus Oxiplex or surgery alone. Patients were assessed 1, 3 and 6

months following surgery using 1) the LSOQ), and 2) clinical evaluations.

Safety was evaluated by analyzing adverse events and clinical symptoms.

Effectiveness was evaluated by scoring the LSOQ to produce composite

scores for leg pain, back pain, and patient satisfaction.

RESULTS: Baseline demographics, surgical procedures, LSOQ scores

and clinical evaluations were balanced between Oxiplex (N5177) and

surgery-only (N5175) groups. All subjects did well following surgery.

There were no cases of CSF leaks in the Oxiplex-treated group and no

differences in laboratory values or vital signs. There were no differences

in adverse events, laboratory values or physical findings between Oxiplex-

treated patients and controls. Oxiplex patients in the challenging patient

population having severe back pain at baseline showed greater reductions

in pain and symptoms from baseline across all LSOQ variables compared

to surgery-only controls. In that population, there was a statistically sig-

nificant reduction of back pain [P50.013] and leg pain [P50.012] in

the Oxiplex group compared to controls at 6 months following surgery.

More Oxiplex patients were satisfied with the outcome of their surgical

treatment than control patients (P50.045). Fewer patients in the Oxiplex

group had abnormal musculoskeletal physical exams at 6 months com-

pared to controls. Patients in the Oxiplex group had less hypoaesthesias,

paraesthesias, and sensory loss compared to controls. Patients in the Ox-

iplex group had fewer re-operations during the 6-month follow-up than

controls (1 vs. 6).

CONCLUSIONS: Taken together, these data demonstrate a consistent

clinically significant improvement in outcomes resulting from the use of

Oxiplex gel in lumbar spine surgery.

FDA DEVICE/DRUG STATUS: Oxiplex: Investigational/Not approved.

doi:10.1016/j.spinee.2008.06.011

10. Embryonic Stem Cells Used for Disc Regeneration in an In Vivo

Model of Disc Degeneration

Ramiro Perez De La Torre, MD1, Hormoz Sheikh, MD2, Mick Perez-Cruet,

MD2, Chistopher Fecek, MSN, MS3, Rasul Chaudhry, PhD4,

David Svinarich, PhD5; 1Oakland University, Troy, MI, USA; 2Southfield,

MI, USA; 3Department of Biological Sciences, Rochester, MI, USA;

4Oakland University, Department of Biological Sciences, Rochester, MI,

USA; 5Providence Hospital and Medical Center, Detroit, MI, USA

BACKGROUND CONTEXT: There is currently no therapy to repair or

restore degenerated intervertebral discs. Embryonic stem (ES) cells can

potentially grow indefinitely in vitro and differentiate into a variety of cell

types. (1) Therefore, ES cells provide an attractive alternative to com-

monly used sources for deriving cells of various lineages for therapeutic

purposes including cells capable of potentially producing nucleus pulpo-

sus. (2) The notochordal cell is felt to be the origin of the intervertebral

disc. As this cell is replaced by terminally differentiated chondrocytes, disc

degeneration begins, most likely as a result of reduced proteoglycan pro-

duction and subsequent loss of water content of the intervertebral disc.

PURPOSE: To report on the potential of murine embryonic stem cells and

their capabilities to differentiate into notochordal cells in an in vivo rabbit

model of disc degeneration

STUDY DESIGN/ SETTING: Basis science experiment

METHODS: A novel In-vivo animal model of disc degeneration was

developed by needle puncture of healthy discs in 16 New Zealand White

rabbits. Rabbits were subjected to magnetic resonance imaging (MRI)

pre-operatively and at 2, 4, and 8 weeks post-operatively. Once radiograph-

ically confirmed, degenerated disc levels where injected with pre-treated

murine embryonic stem cells (ESCs) labeled with a mutant green fluores-

cent protein (GFP). These cells were pre-treated to differentiate along

a chondrocyte cell line. At 8 weeks intervertebral discs were harvested

and analysed with hematoxylin and eosin (H&E) staining, confocal fluo-

rescent microscopy and immuno-histochemical analysis. Three interverte-

bral groups were analyzed: 1. control non-punctured discs (Group A, n532

disc), 2. experimental control punctured disc (Group B, n516 disc), 3. ex-

perimental punctured disc followed by implantation of ESCs (Group C,

n516).

RESULTS: MRI imaging confirmed reproducible intervertebral disc de-

generation at needle punctured segments starting at approximately 2

weeks. Post-mortem histologic analysis of group A intervertebral disc

showed aged chondrocytes and almost complete disappearance of noto-

chordal cells. Group B discs displayed intact annulus fibrosus and gener-

alized disorganization of nucleus pulposus with increased bone

formation . Group C discs showed viable new cartilage forming as well

as notochordal cell growth. Fluorescent analysis was negative for groups

A and B but revealed viable chondrocytes within experimental group C

discs implanted with ESCs. Of note, no inflammatory response as evidence

of cell mediated immune response was noted in Group C discs.

CONCLUSIONS: This study illustrates a novel reproducible model for

the study of disc degeneration as well as disc regeneration using ESCs.

New notochordal cell populations were seen in ES cell injected degener-

ated discs. The lack of immune response to xenograft implanted mouse

cells in an immune competent rabbit model points to an immunologic

sanctuary within the intervertebral disc.

FDA DEVICE/DRUG STATUS: This abstract does not discuss or include

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.012

11. Twenty-four Month Results from a Prospective Randomized

Controlled IDE Study of the DYNESYS Dynamic Stabilization

System

Reginald Davis, MD1, Rick Delamarter, MD2, Jeffrey Wingate, MD3,

John Sherman, MD4, James Maxwell, MD5, William Welch, MD, FACS,

FICS6; 1Greater Baltimore Medical Center, Towson, MD, USA; 2Santa

Monica, CA, USA; 3Michigan Spine Institute, Waterford, MI, USA; 4Edina,

MN, USA; 5Scottsdale Spice Care, Scottsdale, AZ, USA; 6Pittsburgh, PA,

USA

BACKGROUND CONTEXT: Patients with radiculopathy due to spondy-

lolisthesis or stenosing lesions are typically treated with decompression