Epidural Injections for Lumbar Radiculopathy and Spinal Stenosis: A Comparative Systematic Review and Meta-Analysis

Abstract

Background: The prevalence of chronic low back pain and related disability is rapidly increasing as are the myriad treatments, including epidural injections. Even though epidural injections are one of the most commonly performed procedures in managing low back and lower extremity pain, starting in 1901 with local anesthetic alone, conflicting recommendations have been provided, despite the extensive literature. Recently Chou et al performed a technology assessment review for Agency for Healthcare Research and Quality (AHRQ) part of which was published in Annals of Internal Medicine showing lack of effectiveness of epidural steroid injections in managing lumbar radiculopathy and spinal stenosis. In contrast, multiple other publications have supported the efficacy and use of epidural injections. Purpose: To assess the efficacy of 3 categories of epidural injections for lumbar and spinal stenosis: performed with saline with steroids, local anesthetic alone, or steroids with local anesthetic and separate facts from opinions. Data Sources: PubMed, Cochrane Library, US National Guideline Clearinghouse, prior systematic reviews, and reference lists. The literature search was performed through August 2015. Study Selection: Randomized trials, either placebo or active control, of epidural injections for lumbar radiculopathy and spinal stenosis. Data Extraction: Data extraction and methodological quality assessment were performed utilizing Cochrane review methodologic quality assessment and Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB). Evidence was summarized utilizing principles of best evidence synthesis. Data Synthesis: Thirty-nine randomized controlled trials met inclusion criteria. There were 9 placebo-controlled trials evaluating epidural corticosteroid injections, either with sodium chloride solution or bupivacaine, compared to placebo injections. There were 12 studies comparing local anesthetic alone to local anesthetic with steroid. Results A meta-analysis of 5 studies utilizing sodium chloride or bupivacaine with steroid showed a lack of efficacy. A comparison of lidocaine to lidocaine with steroids in 7 studies showed significant effectiveness from baseline to long-term follow-up periods. Meta-analysis showed a similar effectiveness for pain and function without non-inferiority of lidocaine compared to lidocaine with steroid at 3 months and 12 months. Limitations: The review was restricted to the data available with at least 3 months of followup, which excluded some studies. The inclusion criteria were restricted to English language studies. Conclusion: Epidural corticosteroid injections for radiculopathy or spinal stenosis with sodium chloride solution or bupivacaine were shown to be ineffective. Lidocaine alone or lidocaine in conjunction with steroids were significantly effective. Key Words: Epidural injections, epidural steroids, lumbar radiculopathy, spinal stenosis, lidocaine, steroids, bupivacaine