523 - Long-term Evaluation of Re-operation Rates for Lumbar Total Disc Repla...

#523 Long-term Evaluation of Re-operation Rates for Lumbar Total Disc Replacement and Fusion: Analysis of 1,237 Patients

General Session: Best Papers Session

Presented by: S. Blumenthal

Author(s):

S.L. Blumenthal (1)
J.E. Zigler (1)
R.D. Guyer (1)
D.D. Ohnmeiss (2)

(1) Texas Back Institute, Plano, TX, USA
(2) Texas Back Institute Research Foundation, Plano, TX, USA

Abstract

Introduction: Re-operation rates are important in evaluating any spine surgery. The purpose of this study was to analyze re-operations in a large consecutive series of TDR patients, beginning with the first case, and compare it to fusion procedures performed as part of randomized, prospective FDA trials.

Methods: Data were analyzed from a database of all TDR cases performed at a multi-site spine center that participated in five lumbar TDR trials, beginning in March 2000, and that has also used TDRs post-approval. TDR patients were divided into subgroups based on the number of levels operated and those receiving the device as randomized to a TDR investigational group, randomized to TDR as a control group, or received TDR after FDA approval. Fusion patients included in the comparison were randomized to anterior lumbar interbody fusion (ALIF) or 360 degree fusion control groups in TDR trials. Patients undergoing combined TDR/fusion hybrid surgery were also included. Patients undergoing surgery less than 24 months prior to this report were excluded. The longest follow-up was 134 months. Patient selection criteria were very similar in all of the studies with the primary indication being painful disc degeneration unresponsive to at least 6 months of non-operative care. All re-operations were reported including those for wound infection and spinal cord stimulator implantation.

Results: The re-operation rates were 10.4% (110 of 1,058) among TDR procedures; 11.6% (13/112) in the hybrid group, and significantly higher in the fusion group, 20.9% (14/67; p< 0.05). There were no significant differences in re-operation rates among the various TDR subgroups (Figure 1). Forward stepwise logistic regression analysis found that age, gender, body mass index, or the number of levels operated were not significantly related to re-operation (p>0.20).

To evaluate the timing of re-operations, the 343 patients for whom minimum 60 month follow-up was available were analyzed separately (Figure 2). In the fusion and TDR groups, re-operation occurred most often within 24 months, with less than 5% occurring after 60 months post-index surgery.

Conclusion: Re-operation rate was significantly less for TDR than fusion and did not vary significantly between TDR subgroups. Among patients with more than 5-year follow-up, more re-operations occurred within 24 months than during later follow-up. This study found that TDR had a significantly lower re-operation rate than fusion, TDR re-operation rate did not vary with study status or post-approval, and the rate did not increase with long-term follow-up.