A comparative study between interlaminar nerve root targeted epidural versus infraneural transforaminal epidural steroids for treatment of intervertebral disc herniation

Background: Low back pain (LBP) is one of the most common musculoskeletal abnormalities. Epidural corticosteroid injections (ESIs) have been used long time ago for treatment of lumbar radiculopathy or discogenic back pain in case of failed medical and conservative management. Different techniques for ESIs include the interlaminar, the caudal, and the transforaminal approaches. Purpose: The aim of our study is to compare between the efficacy of infraneural transforaminal ESI and lumbar paramedian nerve root targeted interlaminar steroid injection in reduction of unilateral radicular pain secondary to disc prolapse. Patients and Methods: This prospective double-blind randomized study was performed on 40 patients randomized into two equal groups, each of 20: the infraneural transforaminal ESI (IN group) and the interlaminar parasagittal ESI (IL group). Patients with backache without leg radiation, or with focal motor neurological deficit, previous spine surgery, S1 radiculopathy, lumbar ESI in the past month, systemic steroid used recently within 4 weeks before the procedure, allergy to any medication or addiction to opioids, and pregnancy were excluded from the study. The duration and efficacy of pain relief (defined as >= 40% reduction of pain perception) by 0-10 visual analog scale (VAS) is the primary outcome. Functional assessment using Modified Oswestry Disability Questionnaire (MODQ) and possible side effects and complications are the secondary outcomes. Results: The VAS and MODQ scores were significantly lower in both groups in comparison with the basal values. There was also a lower VAS in the infraneural group than the parasagittal (IL) group up to 6 months after injection. Conclusion: The infraneural (IN) epidural steroid is more favorable than the parasagittal (IL) interlaminar epidural steroid owing to its long-term improvement in physical function than the parasagittal technique with no serious side effects.