[Justin]

The Spine Journal
Volume 8, Issue 5, Supplement 1, September-October 2008, Pages 175S-176S
Proceedings of the 23rd Annual Meeting of the North American Spine Society, NASS 24th Annual Meeting

Lumbar Hybrid Arthroplasty Outcomes Analysis

Copyright © 2008 Elsevier Inc. All rights reserved.
Pablo Pazmiño MD1, Carl Lauryssen MD2 and Todd Lanman MD3

1Beverly Spine Institute, Beverly Hills, CA, USA
2Director Neurological Spine Olympia Medical Center, Beverly Hills, CA, USA
3Director Neurological Spine Century City Doctors Hospital, Los Angeles, CA, USA

BACKGROUND CONTEXT: A considerable subset of patients demonstrate symptomatic multiple level lumbar discogenic disease. The rationale behind arthroplasty in preserving adjacent level segments becomes more important in this group of patients given the larger cantilever forces at play. In efforts to preserve motion and limit force concentrations at the remaining lumbar segments hybrid disc arthroplasty is gaining momentum as a new treatment modality.To our knowledge there are no clinical studies which evaluate the outcomes of patients with hybrid disc arthroplasty. The present study evaluates our subset of patients through their patient perceived outcomes, return to sport and their return to work.

PURPOSE: Assess the efficacy and benefits of lumbar hybrid arthroplasty in the treatment of multiple level disc pathology.

STUDY DESIGN/ SETTING: A retrospective observational cohort study of consecutive patients with multiple level lumbar discogenic disease recalcitrant to conservative therapy.

PATIENT SAMPLE: A total of 28 Lumbar arthroplasties in 26 patients were reviewed. Arthroplasty was performed using either the Charite or Prodisc prosthesis in concert with fusion in 26 consecutive patients. 13 males (50%) and 13 females (50%) were evaluated with a mean age of 42 years (range 28 to 58) and mean followup of 20.6 months.The mean duration of back pain before surgery was 3.3 years. All patients were available at each follow-up interval except two patients who were lost to followup.

OUTCOME MEASURES: Outcome variables included radiographic fusion based on postoperative films (2 weeks, 1 month, 3 month, 6 month, 1 year, 18 months, 2 years from surgery), computed tomography (6 months and 1 year) and clinical assessment using visual analog scale for back pain, the Oswestry disability instruments,and the modified Stauffer-Coventry classification.

METHODS: Patient completed ODI,VAS outcome measures and were interviewed on followup to assess return to,type,and frequency of sport, return to and type of work. Determination for return to work and sport was based on postoperative pain, radiographic and CT evidence of interim fusion.

RESULTS: Patients showed statistically significant improvement in ODI scores at all follow-up periods compared to baseline (P<0.001).The mean ODI score at baseline was 67.38, which improved to a mean of 46.62. Patients also showed statistically significant improvement in VAS scores at all follow-up periods compared to baseline (P<0.0001). The mean VAS score at baseline was 7.40, which improved to a mean of 3.73. Improvement at each interval and overall was statistically significant (p<0.05) using the Wilcoxon Rank Sum Test. Using the modified Stauffer-Coventry classification the mean outcome was 3.44 (range 2–4,SD 0.616). The mean interval from surgery to return to work for the 17 patients in employment was 3.61 months or 112.8 days (range 14–351,SD 98.71).The mean interval from surgery for the 20 patients who returned to sports was 3.58 months or 110.89 days (range 1–360,SD 98.51).Among the reasons for the four patients who had not resuming sport, 71% gave pain and 29% gave sociopsychological reasons such as anxiety or lack of time.

CONCLUSIONS: Hybrid lumbar arthroplasty appears to be a safe and effective treatment for painful lumbar discogenic disease.The rate of improvement is rapid and sustained through 1.6 years.This study observes outcomes and times to return to work and sport which may serve as a guide for patient education and post-operative expectation.

FDA DEVICE/DRUG STATUS: Prodisc and Charite Artificial Disc Replacements: Not approved for this indication.