A Prospective Randomized Trial Comparing Effectiveness of Parasagittal and Midline Epidural Steroid Injection in Patients with Lumbar Canal Stenosis Pain.

Background: Low back pain (LBP) due to lumbar spinal stenosis presents a significant clinical challenge. Epidural steroid injections (ESIs) are a common treatment option; however, the optimal injection route remains debated. Objectives: To compare the clinical outcomes of parasagittal interlaminar (PIL) versus midline interlaminar (MIL) ESI in patients with LBP attributed to lumbar spinal stenosis. Methods: This prospective, randomized study included patients with LBP and lumbar stenosis. Participants were randomly assigned to receive ESI via either the PIL or MIL route. Clinical outcomes, including pain intensity (measured by the Numeric Rating Scale [NRS]) and functional disability (assessed using the Modified Oswestry Disability Index [MODQ]), were evaluated at 1- and 3-months post-injection. Results: Analysis revealed a significant reduction in pain intensity (NRS) at 3 months post-injection in the PIL group compared to the MIL group (P = 0.014). Additionally, the PIL group demonstrated significantly lower patient satisfaction scores at 3 months (P = 0.033) and higher MODQ scores at 3 months (P = 0.002) compared to the MIL group. No significant differences were observed between groups at baseline or at the 1-month follow-up for any of the assessed outcomes. Conclusions: This study suggests potential differences in efficacy between parasagittal and midline interlaminar ESIs for lumbar stenosis pain. These findings underscore the need for further research to optimize treatment strategies and improve pain management for patients with this condition.