Results and Analysis of Compassionate Use of Lumbar Disc Replacements (4yr Follow-up)

[Justin]

The Spine Journal
Volume 8, Issue 5, Supplement 1, September-October 2008, Pages 159S-160S
Proceedings of the 23rd Annual Meeting of the North American Spine Society, NASS 24th Annual Meeting

Results and Analysis of Compassionate Use of Lumbar Disc Replacements Up to Four Year Follow-up

Robert Tatsumi MD1, Jason Gallina MD2, L.E.A. Kanim MA, PhD2, Hyun W. Bae MD2, Michael Kropf MD2 and Rick Delamarter MD1

1The Spine Institute, Santa Monica, CA, USA
2Santa Monica, CA, USA

BACKGROUND CONTEXT: Lumbar degenerative disc disease is universal and spinal fusion has been the traditional surgical gold standard treatment for intractable pain due to degenerative disc disease. Concerns with fusion morbidity, prolonged recovery and accelerated adjacent segment degeneration have led researchers to develop motion-preserving artificial disc replacement (ADR) as alternative to fusion. ProDisc-L™ (Synthes Spine, West Chester, PA) is an ADR that has been approved by the FDA with recent prospective randomized control trial (PRCT) documented results demonstrating superior outcomes in one level ADR patients compared with circumferential fusion.

PURPOSE: To evaluate outcome and radiographic data in patients implanted because they did not meet eligibility criteria for the ProDisc-L PRCT. These patients received ProDisc-L under the compassionate use exemption by the FDA.

STUDY DESIGN/ SETTING: Prospective clinical trial evaluating patients implanted with the ProDisc-L on a compassionate use exemption with clinical and radiologic follow-up at at 6 weeks, 3 months, 6 months, and annually.

PATIENT SAMPLE: Forty patients with lumbar disc degeneration with radicular pain who were excluded from ProDisc-L RCT were offered ProDisc-L under the compassionate use exemption. Reasons for ineligibility included 3 level disc degeneration (27), severe facet arthrosis (6), prior lumbar fusion (4), >50% facet resected (1), severe central stenosis (1), and age >60 y/o (1).

OUTCOME MEASURES: Patients completed Oswestry Disability Index (ODI), Visual Analogue Scale pain (VAS-pain), Visual Analogue Scale Satisfaction (VAS-Sat) and answered the question “would you have surgery again?” at the scheduled follow-up visits.

METHODS: In addition to outcome measurements, radiographs and physical assessments were performed at each scheduled visit. Changes from pre-operative pain and disability and overall satisfaction were separately evaluated as a function of treatment using repeated measures mixed design analysis of variance.

RESULTS: Forty patients underwent ProDisc-L. The mean age was 45 years old, 52% of the patients were male, and 15% of the patients were smokers. Three patients had 1-level ProDisc-L (ADR-1), 10 patients had two-level ProDisc-L (ADR-2) and 27 patients had 3-level ProDisc-L (ADR-3). Follow up was 2–4 years . At 24 months, all patients had a significant reduction in ODI and VAS-pain scores, improved VAS-satisfaction scores and >75% of the patients stated they would definitely “have surgery again.” The ADR-3 patients had the greatest ODI improvement (25.7 points) and the ADR-1 patients had the greatest VAS pain improvement (5.3 points) and had the highest VAS-satisfaction scores (6.6cm). One patient required prothesis removal and fusion secondary to pain.

CONCLUSIONS: Patients who did not meet the strict criteria for the ProDisc-L PRCT but still received the device under the compassionate allowance were highly satisfied, had decreased pain, and had improved functional outcomes. ADR-1 patients had the highest pain relief and satisfaction scores and ADR-3 patients achieved the best improvement in disability. There was no statistical difference in outcomes scores between compassionate use ProDisc-L patients and the published RCT ProDisc-L patients. These results demonstrate “non-ideal” patients benefit from ProDisc-L and have similar functional and disability outcomes to the published RCT Pro-Disc patient cohort.

FDA DEVICE/DRUG STATUS: ProDisc-L: Investigational/Not approved.

Copyright © 2008 Elsevier Inc. All rights reserved.