Epidural injections with or without steroids in managing chronic low back pain secondary to lumbar spinal stenosis: a meta-analysis of 13 randomized controlled trials

BACKGROUND Epidural injections of anesthetic with or without steroids are widely used for treating lumbar spinal stenosis, a common cause of chronic low back pain, but there is a lack of rigorous data comparing the effectiveness of epidural injections of anesthetic with and without steroids. This meta-analysis presents a current, comprehensive picture of how epidural injections of anesthetic with steroids compare with those using local anesthetic alone. METHODS PubMed, Embase, Web of Science, and Cochrane Library databases were searched from their inception through February 5, 2015. Weight mean difference, risk ratio, and 95% confidence intervals were calculated. A random effects model or fixed effects model was used to pool the estimates, according to the heterogeneity between the included studies. RESULTS We included 13 randomized controlled trials, involving 1,465 patients. Significant pain relief (≥50%) was demonstrated in 53.7% of patients administered with epidural injections of anesthetic with steroids (group 1) and in 56.4% of those administered with local anesthetic alone (group 2). Patients showed a reduction in numeric rating scale pain score of 3.7 and 3.6 in the two groups, respectively. Significant functional improvement was achieved in 65.2% of patients in group 1 and 63.1% of patients in group 2, with Oswestry Disability Index reductions of 13.8 and 14.5 points, respectively. The overall number of injections per year was 3.2±1.3 and 3.4±1.2 with average total relief per year of 29.3±19.7 and 33.8±19.3 weeks, respectively. The opioid intakes decreased from baseline by 12.4 and 7.8 mg, respectively. Among the outcomes listed, only total relief time differed significantly between the two groups. CONCLUSION Both epidural injections with steroids or with local anesthetic alone provide significant pain relief and functional improvement in managing chronic low back pain secondary to lumbar spinal stenosis, and the inclusion of steroids confers no advantage compared to local anesthetic alone.