Addition of Fusion to Decompression for Grade I Degenerative Lumbar Spondylolisthesis is Associated With Greater Patient-Reported Outcome Improvements at Twenty-Four-Month Follow-Up: A Multicenter Study Using the Quality Outcomes Database

Abstract

Abstract INTRODUCTION Extensive investigation has not ascertained the ideal surgical management of grade 1 lumbar spondylolisthesis. Using the large, multicenter, prospectively collected Quality Outcomes Database (QOD), we compared 24-mo outcomes for patients undergoing decompression alone vs decompression and fusion. METHODS Patients undergoing single-level surgery from 7/1/2014 to 6/30/2016 were identified. The primary outcome measure, 24-mo Oswestry Disability Index (ODI) change, was analyzed with univariate and multivariable linear regression. EQ-5D scores, numerical rating scale (NRS) back and leg pain scores, and North American Spine Society patient satisfaction scores were also analyzed. RESULTS Of the 608 patients (85.5% with at least 24-mo follow-up) who met the inclusion criteria, 140 (23.0%) underwent decompression alone and 468 (77.0%) underwent decompression and fusion. The 24-mo change in ODI was significantly greater in the fusion group than the decompression-only group (−25.8 ± 20.0 vs −15.2 ± 19.8, P < .001). Fusion remained independently associated with 24-mo ODI change in our multivariable model (B = −7.05, 95% CI 10.70-3.39, P = < .001). Patients in the fusion group were significantly more likely to reach minimal clinically important difference (MCID, 12.8 points) in ODI at 24 mo (73.3% vs 56.0%, P = < .001), and to experience significantly greater NRS back pain improvement at 24-mo follow-up (3.8 ± 3.1 vs −1.8 ± 3.9, P < .001). Fusion was also independently associated with achieving MCID for ODI at 24 mo in our logistic regression model (OR 1.767, 95% CI 1.058-2.944, P = .029). CONCLUSION The results of our study suggest that decompression plus fusion may offer superior outcomes to decompression alone in patients with grade 1 lumbar spondylolisthesis at 24 mo. Longer-term follow-up is warranted to assess whether this effect is sustained.