Decompression alone versus decompression with fusion in patients with lumbar spinal stenosis with degenerative spondylolisthesis: a systematic review and meta-analysis

Introduction Surgical decompression is standard care in the treatment of degenerative spondylolisthesis in patients with symptomatic lumbar spinal stenosis, but there remains controversy over the benefits of adding fusion. The persistent lack of consensus on this matter and the availability of new data warrants a contemporary systematic review and meta-analysis of the literature. Methods Multiple online databases were systematically searched up to October 2022 for randomized controlled trials (RCTs) and prospective studies comparing outcomes of decompression alone versus decompression with fusion for lumbar spinal stenosis in patients with degenerative spondylolisthesis. Primary outcome was the Oswestry Disability Index. Secondary outcomes included leg and back pain, surgical outcomes, and radiological outcomes. Pooled effect estimates were calculated and presented as mean differences (MD) with their 95% confidence intervals (CI) at two-year follow-up. Results Of the identified 2403 studies, eventually five RCTs and two prospective studies were included. Overall, most studies had a low or unclear risk of selection bias and most studies were focused on low grade degenerative spondylolisthesis. All patient-reported outcomes showed low statistical heterogeneity. Overall, there was high-quality evidence suggesting no difference in functionality at two years of follow-up (MD − 0.31, 95% CI − 3.81 to 3.19). Furthermore, there was high-quality evidence of no difference in leg pain (MD − 1.79, 95% CI − 5.08 to 1.50) or back pain (MD − 2.54, 95% CI − 6.76 to 1.67) between patients undergoing decompression vs. decompression with fusion. Pooled surgical outcomes showed less blood loss after decompression only, shorter length of hospital stay, and a similar reoperation rate compared to decompression with fusion. Conclusion Based on the current literature, there is high-quality evidence of no difference in functionality after decompression alone compared to decompression with fusion in patients with degenerative lumbar spondylolisthesis at 2 years of follow-up. Further studies should focus on long-term comparative outcomes, health economic evaluations, and identifying those patients that may benefit more from decompression with fusion instead of decompression alone. This review was registered at Prospero (CRD42021291603).