71SProceedings of the NASS 23rd Annual Meeting / The Spine Journal 8 (2008) 1S–191S

PURPOSE: To compare the results of the 2-level lumbar surgery IDE

study to the 1-level lumbar surgery IDE study using the ProDisc�-L

TDR or circumferential fusion.

STUDY DESIGN/ SETTING: The 2-level prospective, randomized, mul-

ticenter, Food and Drug Administration (FDA)-regulated IDE clinical trial

patient population was compared to the 1-level prospective, randomized,

multicenter, Food and Drug Administration (FDA)-regulated IDE clinical

trial patient population.

PATIENT SAMPLE: A total of 237 randomized 2-level patients at 16

sites were compared to 236 randomized 1-level patients at 17 sites.

OUTCOME MEASURES: Patient self-assessments, e.g., Oswestry

Disability Index (ODI) low back pain questionnaire, SF-36 Health Survey,

Visual Analog Scale (VAS) for pain and satisfaction, physical and neuro-

logical examination, and radiographic evaluation.

METHODS: Patients were evaluated pre-operatively and post-operatively

at 6 weeks, 3, 6, 12, 18, and 24 months.

RESULTS: At 24 months, 90.0% of 2-level ProDisc�-L TDR patients re-

ported improvement in ODI from pre-operative levels compared to 91.8%

of 1-level ProDisc�-L TDR patients; 73.3% of 2-level ProDisc�-L TDR

patients and 77.2% of 1-level ProDisc�-L TDR patients met the 15 point

ODI improvement criteria. In the Fusion group, at 24 months, 86.7% of 2-

level Fusion patients reported improvement in ODI from pre-operative

levels compared to 84.5% of 1-level Fusion patients; 55.9% of 2-level Fu-

sion patients and 64.8% of 1-level Fusion patients met the 15 point ODI

improvement criteria. In 2-level patients, overall neurological success of

the ProDisc�-L TDR group was statistically superior to the Fusion group

(ProDisc�-L: 89.2%; Fusion: 77.9%; p50.0260) which was similar to 1-

level patients where ProDisc�-L TDR was also statistically superior to the

Fu-sion group (ProDisc�-L: 91.2%, Fusion: 81.4%; p50.0341). In 2-level

patients, the ProDisc�-L TDR patients recorded SF-36 scores significantly

higher than the Fusion group at all follow-up time points. In 1-level

pa-tients, SF-36 scores were not significantly different between the two

patient groups. The VAS pain assessment showed statistically significant

improvement from pre-operative scores regardless of treatment (p!0.0001)

in 2-level patients, and at 24 months, the ProDisc�-L TDR group showed

statistically significantly higher pain re-duction than the Fusion group

(p50.0466). In 1-level patients, VAS pain scores at 24 months were not

statisti-cally significant between the two groups. Radiographic range of

motion was maintained within normal func-tional range in over 90% of

ProDisc�-L TDR patients regardless of number of surgery levels.

CONCLUSIONS: Results suggest that TDR patients are presenting with

overall improvement at 2 years comparable to circumferential fusion

patients. When measured against the 1-level IDE trial results, 2-level

ProDisc�-L patients are experiencing similar clinical outcomes as 1-level

ProDisc�-L patients.

FDA DEVICE/DRUG STATUS: ProDisc-L (1 level): Approved for this

indication; PoaDisc-L (2 level): Investigational/Not approved.

doi:10.1016/j.spinee.2008.06.167

137. Clinical Practice Guideline-based Treatment is Not Effective for

All Patients with Acute Lower Back Pain: A Randomized Controlled

Clinical Trial

Paul Bishop, DC, MD, PhD1, Charles Fisher, MD, MSc, FRCS1,

Jeffrey Quon, DC, PhD, FCCS2, Marcel Dvorak, MD, FRCS1; 1Combined

Neurosurgical & Orthopaedic Spine Program, Department of

Orthopaedics, University of Birtish Columbia, Vancouver, British

Columbia, Canada; 2Department of Healthcare and Epidemiology,

University of British Columbia, Vancouver, British Columbia, Canada

BACKGROUND CONTEXT: Clinical practice guideline concordant

treatment (GCtx) has been shown to be more effective than CPG discor-

dant care (Dtx) in a heterogeneous cohort of patients with acute lower back

pain (ALBP). However, patients with underlying spine pathology (e.g. ste-

nosis, disc degeneration, facet joint arthropathy) or without identifiable

spine pathology may all present solely with ALBP. At present, it is un-

known if the presence or the nature of any underlying spine pathology in-

fluences the outcome of GCtx.

PURPOSE: To determine if GCtx is more effective than Dtx in patients

with differing underlying spine pathology who present with ALBP.

STUDY DESIGN/ SETTING: Two-arm, randomized controlled trial with

stratified analysis.

PATIENT SAMPLE: Inclusion: Ages 19–59; QTFSD I, II ALBP!4 weeks.

Exclusion: ‘‘Red Flag’’ conditions, co-morbidities contraindicating GCtx.

OUTCOME MEASURES: Primary outcome: Difference between GCtx

and Dtx Roland Morris Disability (RDQ) scores at 16 weeks post baseline

between study groups. Secondary outcomes: differences in Bodily Pain

(BP), Physical Functioning (PF) SF-36 domain scores at 16 weeks.

METHODS: Patients were assessed by a spine physician and randomized to

GCtx or Dtx. Patients were stratified on the basis of CT or MRI evidence of:

1) spinal stenosis; 2) disc degeneration; 3) facet joint arthropathy; or 4) no

identifiable pathology. Hospital / University Ethics approval was obtained.

RESULTS: 88 patients recruited; 39 in GCtx & 38 in Dtx group com-

pleted the study. Baseline prognostic variables were evenly distributed be-

tween groups. Outcomes: mean difference in16 week RDQ, BP and PF

scores between GCtx and Dtx was statistically greatest in group 4

(p!0.001). There was no significant clinical improvement in RDQ, BP

or PF scores in either the GCtx or Dtx in group 2.

CONCLUSIONS: GCtx was more effective than Dtx in patients with no

identifiable spine pathology and ineffective and equivalent to Dtx in pa-

tients with underlying disc degeneration. Thus, the outcome of non-oper-

ative treatment of acute lower back pain is influenced by the presence

and the type of underlying spine pathology.

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

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.168

138. Weight Loss in Overweight and Obese Patients Following

Successful Lumbar Decompression

Ryan Garcia, MD1, Patrick Messerschmitt, MD1, Christopher Furey, MD1,

Henry Bohlman, MD1, Ezequiel Cassinelli, MD2; 1Case Western Reserve

University, Cleveland, OH, USA; 2Peachtree Orthopeadic Clinic, Atlanta,

GA, USA

BACKGROUND CONTEXT: Neurogenic claudication secondary to

lumbar stenosis is often cited by overweight and obese patients as a limiting

factor to losing weight. Many patients believe that increased activity and

subsequent weight reduction will occur following symptomatic relief.

PURPOSE: The objective of this study was to evaluate weight loss in

overweight and obese patients obtaining substantial pain relief after lumbar

decompression surgery for spinal stenosis.

STUDY DESIGN/ SETTING: Retrospective review.

PATIENT SAMPLE: All overweight and obese patients were included

who underwent lumbar decompression surgery from January 2003 to June

2005.

OUTCOME MEASURES: Changes in patient body weight and body

mass index (BMI) in overweight and obese patients after lumbar decom-

pression surgery were assessed at intermediate follow-up (2 to 4.3 years).

Preoperative and postoperative body weight and body mass index were

collected, as were Zurich Claudication Questionnaire (ZCQ) scores.

METHODS: Changes in patient body weight and body mass index (BMI)

in overweight and obese patients after lumbar decompression surgery were

assessed at intermediate follow-up (2 to 4.3 years). Preoperative and post-

operative body weight and body mass index were collected, as were Zurich

Claudication Questionnaire (ZCQ) scores. Inclusion criteria were: age 35

to 65, chronic neurogenic claudication symptoms, primary lumbar decom-

pression with or without arthrodesis, and Zurich Claudication Question-

naire satisfaction scores of good/excellent. Exclusion criteria were:

preoperative body mass index!25 kg/m2, functionally limiting or poorly