Clinical Question

What are the benefits and harms of lumbar fusion for degenerative low back pain?

Bottom Line

Lumbar fusion for degenerative spinal disease appears to be most beneficial for patients undergoing the procedure for spondylolisthesis, but it is of little clear benefit for patients with other indications, such as spinal stenosis or chronic back pain. The risk of reoperation or complications is greater for patients with spinal stenosis who undergo fusion compared with those who have decompression alone. (Level of Evidence = 1a–)

Synopsis

Spinal fusion is an expensive procedure of uncertain value that has high cost and regional variability in annual incidence. The authors performed a careful search of the literature to identify randomized trials (n = 19), cohort studies (n = 16 prospective and 15 retrospective), and registries (n = 15) that compared the outcomes of lumbar fusion, decompression, and/or nonoperative care for degenerative spine disease. They performed a comprehensive search to identify randomized trials and cohort studies with at least two arms, at least two participants per arm, and with at least 12 months of follow-up. Studies were generally at high risk of bias because of inadequate randomization, masking, and allocation concealment; this would tend to bias the studies in favor of active therapy. This synopsis focuses primarily on the results from the randomized trials.

Regarding the Oswestry Disability Index (a 100-point scale), there was a statistically, but not clinically, significant 5-point improvement with fusion compared with nonoperative care for patients with chronic back pain, and a statistically and clinically significant 17-point improvement for those with spondylolisthesis as the indication. Results were similar for a visual analog scale measuring leg pain, with the improvement having statistical and clinical significance for patients with spondylolisthesis (2.2 points on a 10-point scale). Leg pain was largely evaluated in registry studies, and was not more improved by fusion than by decompression in patients with any indication. Patient satisfaction was greater for fusion compared with nonoperative care among patients with spondylolisthesis, but much less so for those with low back pain. There were no significant differences in risk of death, although confidence intervals were quite broad. Based mainly on registry and cohort studies, the risk of reoperation was greater for patients undergoing fusion than decompression if the indication was spinal stenosis (relative risk [RR] = 1.17; 95% confidence interval [CI], 1.06 to 1.28), but the opposite was true if spondylolisthesis was the indication (RR = 0.75; 95% CI, 0.68 to 0.83). Finally, based on a mix of study designs, the risk of complications was greater for patients undergoing fusion than decompression alone (RR = 1.70; 95% CI, 1.50 to 1.92).

Study design: Meta-analysis (other)

Funding source: Unknown/not stated

Setting: Outpatient (specialty)

Reference:YavinDCashaSWiebeSet alLumbar fusion for degenerative disease: a systematic review and meta-analysis. Neurosurgery2017;80(5):701–715.