Background: Epidural injections are one of the commonly performed procedures in managing low back and lower extremity pain. In the past, Pinto et al and Chou et al performed systematic reviews and meta-analyses with a recent update from Oliveira et al showing lack of effectiveness of epidural steroid injections in managing lumbar radiculopathy. In contrast, multiple other systematic reviews and meta-analyses have supported the efficacy and use of epidural injections utilizing fluoroscopic guidance.
Study design: A systematic review and meta-analysis of randomized controlled trials (RCTs) of epidural injections in managing chronic low back and lower extremity pain with sciatica or lumbar radiculopathy.
Objectives: To assess the efficacy of 3 categories of epidural injections for lumbar radiculopathy or sciatica performed utilizing saline with steroids, local anesthetic alone, or steroids with local anesthetic.
Methods: In this systematic review and meta-analysis, RCTs with a placebo control or an active control design, performed under fluoroscopic guidance, with at least 6 months of followed-up were included. The outcome measures were pain relief and functional status improvement. Significant improvement was defined as 50% or greater pain relief and functional status improvement. Literature search was performed through January 2021. Methodological quality assessments were performed. Evidence was summarized utilizing principles of best evidence synthesis.
Results: In this analysis, a total of 21 RCTs were utilized with at least 6 months of follow-up and performed under fluoroscopic guidance. However, only 6 of 25 trials from Cochrane review met inclusion criteria for this review. Based on qualitative analysis, of the 21 trials included in the present analysis, there was only one placebo-controlled trial found to be negative. With conventional meta-analysis, there was no significant difference among the studies because all of the studies were active control with local anesthetic or local anesthetic and steroids. Further, with single-arm analysis, of the 5 trials included in that portion of the study, significant improvement was seen with local anesthetic alone compared to local anesthetic and steroids. There was a tendency for better improvement with steroids in terms of both pain relief and functional status. The level of evidence is Level I or strong for local anesthetic with steroids and Level I to II or moderate to strong for local anesthetic as a single agent based on multiple relevant high quality RCTs.
Limitations: Despite multiple trials available, there is a paucity of true RCTs performed under fluoroscopic guidance with any of the approaches.
Conclusion: Epidural injections with or without steroids for radiculopathy showed significant effectiveness with Level I or strong evidence for local anesthetic with steroids and Level II to I or moderate to strong evidence with local anesthetic alone.
Keywords: caudal epidural injections; epidural injections; interlaminar epidural injections; local anesthetic; lumbar radiculopathy; sciatica; steroids; transforaminal epidural injections; Chronic low back pain.