Background: Epidural injections are among the most commonly performed procedures for managing low back and lower extremity pain. Pinto et al and Chou et al previously performed systematic reviews and meta-analyses, which, along with a recent update from Oliveira et al showing the lack of effectiveness of epidural steroid injections in managing lumbar disc herniation, spinal stenosis, and radiculopathy. In contrast to these papers, multiple other systematic reviews and meta-analyses have supported the effectiveness and use of epidural injections utilizing fluoroscopically guided techniques. A major flaw in the review can be related to attributing active-controlled trials to placebo-controlled trials. The assumption that local anesthetics do not provide sustained benefit, despite extensive evidence that local anesthetics provide long-term relief, similar to a combination of local anesthetic with steroids is flawed.
Study design: The Cochrane Review of randomized controlled trials (RCTs) of epidural injections in managing chronic low back and lower extremity pain with sciatica or lumbar radiculopathy were reanalyzed using systematic methodology and meta-analysis.
Objectives: To re-evaluate Cochrane data on RCTs of epidural injections in managing chronic low back and lower extremity pain with sciatica or lumbar radiculopathy utilizing qualitative and quantitative techniques with dual-arm and single-arm analysis.
Methods: In this systematic review, we have used the same RCTs from the Cochrane Review of a minimum of 20% change in pain scale or significant pain relief of >= 50%. The outcome measures were pain relief and functional status improvement. Significant improvement was defined as 50% or greater pain relief and functional status improvement. Our review was performed utilizing the Cochrane Review methodologic quality assessment and the Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB). Evidence was summarized utilizing the principles of best evidence synthesis and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system. Clinical relevance of the pragmatic nature of each study was assessed.
Results: In evaluating the RCTs in the Cochrane Review, 10 trials were performed with fluoroscopic guidance. Utilizing conventional dual-arm and single-arm meta-analysis, the evidence is vastly different from the interpretation of the data within the Cochrane Review. The overall combined evidence is Level I, or strong evidence, at one and 3 months, and Level II, or moderate evidence, at 6 and 12 months.
Limitations: The limitation of this study is that only data contained in the Cochrane Review were analyzed.
Conclusion: A comparative systematic review and meta-analysis of the Cochrane Review of randomized controlled trials (RCTs) of epidural injections in managing chronic low back and lower extremity pain with sciatica or lumbar radiculopathy yielded different results. This review, based on the evidence derived from placebo-controlled trials and active-controlled trials showed Level I, or strong evidence, at one and 3 months and Level II at 6 and 12 months. This review once again emphasizes the importance of the allocation of studies to placebo-control and active-control groups, utilizing standards of practice with inclusion of only the studies performed under fluoroscopic guidance.
Keywords: caudal epidural injections; epidural injections; interlaminar epidural injections; local anesthetic; lumbar radiculopathy; sciatica; steroids; transforaminal epidural injections; Chronic low back pain.