Background: Among the multiple interventions used in managing chronic spinal pain, lumbar epidural injections have been used extensively to treat lumbar radicular pain. Among caudal, interlaminar, and transforaminal, transforaminal epidural injections have gained rapid and widespread acceptance for the treatment of lumbar and lower extremity pain. The potential advantages of transforaminal over interlaminar and caudal, include targeted delivery of a steroid to the site of pathology, presumably onto an inflamed nerve root. However, there are only a few well-designed, randomized, controlled studies on the effectiveness of steroid injections. Consequently, multiple systematic reviews with diverse opinions have been published.
Study design: A systematic review of therapeutic transforaminal epidural injection therapy for low back and lower extremity pain.
Objective: To evaluate the effect of therapeutic transforaminal lumbar epidural steroid injections in managing low back and lower extremity pain.
Methods: The available literature on lumbar transforaminal epidural injections in managing chronic low back and lower extremity pain was reviewed. The quality assessment and clinical relevance criteria utilized were the Cochrane Musculoskeletal Review Group criteria as utilized for interventional techniques for randomized trials and by the Newcastle-Ottawa Scale criteria for observational studies. Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to December 2011, and manual searches of the bibliographies of known primary and review articles. The level of evidence was classified as good, fair, or poor based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF).
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: For this systematic review, 70 studies were identified. Of these, 43 studies were excluded and a total of 27 studies met inclusion criteria for methodological quality assessment with 15 randomized trials (with 2 duplicate publications) and 10 non-randomized studies. For lumbar disc herniation, the evidence is good for transforaminal epidural with local anesthetic and steroids, whereas it was fair for local anesthetics alone and the ability of transforaminal epidural injections to prevent surgery. For spinal stenosis, the available evidence is fair for local anesthetic and steroids. The evidence for axial low back pain and post lumbar surgery syndrome is poor, inadequate, limited, or unavailable.
Limitations: The limitations of this systematic review include the paucity of literature.
Conclusion: In summary, the evidence is good for radiculitis secondary to disc herniation with local anesthetics and steroids and fair with local anesthetic only; it is fair for radiculitis secondary to spinal stenosis with local anesthetic and steroids; and limited for axial pain and post surgery syndrome using local anesthetic with or without steroids.