Lumbar Epidural Steroid Injection

Lumbar epidural steroid injections (LESIs) are minimally invasive, image-guided procedures used to treat lumbosacral radicular pain by depositing corticosteroid, with or without local anesthetic, into the epidural space. Radicular pain results from inflammation, irritation, or compression of a lumbar or sacral nerve root. This pain commonly presents in the low back and radiates into the buttock or lower extremity in a dermatomal distribution. Lumbar disc herniation is the most common cause; degenerative lateral recess or foraminal stenosis, spondylolisthesis, postoperative epidural fibrosis, and facet synovial cysts may also produce radicular symptoms. LESIs are not routinely indicated for isolated axial low back pain without radicular features. LESIs occupy an intermediate role between noninterventional treatment and surgical decompression. In appropriately selected patients with persistent, function-limiting radicular pain despite conservative measures, an injection may provide sufficient symptom relief to facilitate physical therapy, maintenance of daily activity, and reduction of analgesic requirements. LESIs do not correct the underlying structural pathology and should not delay urgent evaluation of cauda equina syndrome, progressive motor deficit, suspected infection, fracture, or malignancy. Three lumbar epidural approaches are used: interlaminar, transforaminal, and caudal. The transforaminal approach permits selective delivery near the affected nerve root and ventral epidural space. In contrast, interlaminar and caudal approaches generally provide broader epidural distribution and may be useful for multilevel symptoms, bilateral disease, or altered postsurgical anatomy. Approach selection should be individualized according to clinical presentation, imaging findings, prior surgery, and procedural risk. Fluoroscopic guidance with contrast confirmation is routinely used to optimize needle placement and assess injectate spread. Evidence supports realistic, time-limited expectations. A 2025 systematic review from the American Academy of Neurology concluded that epidural steroid injections probably reduce short-term pain and disability in cervical and lumbar radiculopathy, while evidence remains insufficient to establish durable long-term pain relief. Similarly, a 2024 systematic review and meta-analysis found short- to medium-term pain benefit for sciatica caused by lumbar disc herniation but no clear improvement in functional recovery. Although serious complications are uncommon, they can be consequential. Careful patient selection, image-guided technique, appropriate use of contrast, and vigilance for intravascular or intrathecal injection are essential components of safe practice. LESIs should therefore be incorporated into a multimodal, patient-centered treatment plan rather than used as a stand-alone or indefinitely repeated intervention.