An Updated Systematic Review and Meta-Analysis of Fluoroscopic Caudal, Interlaminar, and Transforaminal Epidural Injections in Lumbar Disc Herniation.

BACKGROUND: Epidural injections are among the most frequently used interventions for management of low back and lower extremity pain. These injections are administered through caudal, interlaminar, and transforaminal approaches. Despite widespread use, controversy persists regarding effectiveness, appropriateness, medical necessity, and clinical indications. Although numerous studies have evaluated efficacy, there has been limited advancement in high-quality randomized evidence. In addition, multiple systematic reviews have repeatedly analyzed the same clinical trials, resulting in an evidence base that remains limited, inconsistent, and, at times, contradictory. OBJECTIVES: To synthesize the latest clinical evidence evaluating the efficacy of the 3 epidural injection approaches: caudal, interlaminar, and transforaminal for the management of lumbar disc herniation. STUDY DESIGN: A systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating transforaminal, interlaminar, and caudal epidural injections for management of chronic low back and lower extremity pain associated with lumbar disc herniation and radiculitis. METHODS: Randomized controlled trials with either placebo-controlled or active-controlled designs, performed under fluoroscopic guidance and including a minimum follow-up of 6 months, were identified and reviewed. Methodological quality was assessed using the Cochrane risk of-bias criteria and the Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB) for randomized therapeutic trials. The certainty of the evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. Levels of evidence were determined using best-evidence synthesis with modified qualitative grading ranging from Level I to Level V. A comprehensive literature search was conducted across multiple databases to identify publications from 2020 through March 2026. Additional studies were identified through manual searches of the bibliographies of relevant review articles, systematic reviews, and clinical guidelines. Eligible trials underwent quality assessment and were incorporated into both qualitative and quantitative evidence synthesis. OUTCOME MEASURES: The primary outcome measure was proportion of patients achieving significant pain relief and functional improvement, defined as at least a 50% improvement sustained for at least 3 months. Duration of benefit was categorized as short-term relief (< 6 months) or long-term relief (> 6 months). RESULTS: A total of 21 trials met the inclusion criteria. Among these, 7 evaluated caudal epidural injections, 12 evaluated transforaminal epidural injections, and 10 evaluated lumbar interlaminar epidural injections. Qualitative and quantitative analyses included conventional dual-arm and single-arm analyses for interlaminar epidural injections, as well as single-arm analyses for caudal and transforaminal epidural injections, depending on the approach to the epidural space. The findings demonstrated Level I evidence supporting the use of local anesthetic with steroids and Level II evidence supporting local anesthetic alone for both transforaminal and interlaminar approaches. For the caudal approach, Level II evidence supported both local anesthetics with steroids and local anesthetics alone for achieving short-term and long-term relief. LIMITATIONS: Available literature remains limited, with few studies reporting intermediate- or long-term outcomes of at least 6 months using appropriate outcome measures. Conventional dual-arm meta-analysis was feasible only for interlaminar epidural injections. CONCLUSION: Epidural injections using local anesthetic with steroids demonstrated Level I evidence for both transforaminal and interlaminar approaches, whereas local anesthetic alone demonstrated Level II evidence. While, caudal epidural injections provided Level II evidence for both local anesthetics with steroids and local anesthetics alone.