Lumbar Interlaminar Epidural Injections in Managing Chronic Low Back and Lower Extremity Pain: A Systematic Review

Background: Low back pain with or without lower extremity pain is the most common problem among chronic pain disorders with significant economic, societal, and health impact. Epidural injections are one of the most commonly performed interventions in the United States in managing chronic low back pain. However the evidence is highly variable among different techniques utilized - namely interlaminar, caudal, transforaminal - and for various conditions, namely - intervertebral disc herniation, spinal stenosis, and discogenic pain without disc herniation or radiculitis. Study Design: A systematic review of lumbar interlaminar epidural injections with or without steroids. Objective: To evaluate the effect of lumbar interlaminar epidural injections with or without steroids in managing various types of chronic low back and lower extremity pain emanating as a result of disc herniation or radiculitis, spinal stenosis, and chronic discogenic pain. Methods: Review of the literature and methodologic quality assessment were performed according to the Cochrane Musculoskeletal Review Group Criteria as utilized for interventional techniques for randomized trials and the Agency for Healthcare Research and Quality (AHRQ) criteria for observational studies. The level of evidence was classified as Level I, II, or III based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF) for therapeutic interventions. Data sources included relevant literature of the English language identified through searches of PubMed and EMBASE from 1966 to November 2008, and manual searches of bibliographies of known primary and review articles. Results of analysis were performed for multiple conditions separately. Outcome Measures: The primary outcome measure was pain relief (short-term relief = up to 6 months and long-term > 6 months). Secondary outcome measures were improvement in functional status, psychological status, return to work, and reduction in opioid intake. Results: The available literature included only blind epidural injections without fluoroscopy The indicated evidence is positive (Level II-2) for short-term relief of pain of disc herniation or radiculitis utilizing blind interlaminar epidural steroid injections with lacking of evidence with Level III for long-term relief for disc herniation and radiculitis. The evidence is lacking with Level III for short and long-term relief for spinal stenosis and discogenic pain without radiculitis or disc herniation utilizing blind epidural injections. Limitations: The limitations of this study include paucity of literature, lack of quality evidence, lack of fluoroscopic procedures, and lack of applicable evidence in contemporary interventional pain management practices. Conclusion: The evidence based on this systematic review is limited for blind interlaminar epidurals in managing all types of pain except for short-term relief of pain secondary to disc herniation and radiculitis. This evidence does not represent contemporary interventional pain management practices and also the evidence may not be extrapolated to fluoroscopically directed lumbar interlaminar epidural injections.