Comparative Efficacy and Safety of Fluoroscopy-guided Caudal Epidural Steroid Injection and Transforaminal Epidural Steroid Injection for Unilateral L5-S1 Paracentral Discogenic Radicular Pain

Introduction: Epidural steroid injection (ESI) is one of the key management strategies in the management of discogenic radicular pain. This study aims to compare the efficacy and safety of fluoroscopy-guided ESI through caudal (cESI) and Transforaminal (tf ESI) routes for unilateral paracentral L5-S1 discogenic radicular pain. Materials and Methods: This prospective non-randomized comparative study conducted between January 2023 and January 2024 in a tertiary care hospital included patients presenting with unilateral paracentral L5-S1 discogenic radicular pain who failed 6 weeks of conservative care. The pain and functional outcome was analyzed using numerical pain rating scale (NPRS) and Oswestry disability index, respectively, at baseline, 3-week, 6-week, and 6-month post-intervention. procedure failure is defined as NPRS score improvement <50% or ODI improvement <40% of baseline. Other outcomes analyzed were the duration of the procedure, and fluoroscopy shots used during the procedure. Results: We enrolled 60 patients in the study, 54 patients were available till the final follow-up with 26 patients in the cESI group and 28 patients in the tf ESI group. The mean age of the cESI group (M: F 12:14) and tf ESI group (M:F 10:18) was 36.1 (±4.1) years and 38.9 (±3.9) years, respectively. The pain and functional scores were significantly reduced compared to the baseline scores in both the groups (P < 0.001) and the reduction between the two groups was comparable at every follow-up. The tf ESI group experienced significantly more failures (n = 8) at 6 months compared to the cESI group (n = 2) (P = 0.048). The tf ESI group had significantly longer mean procedure time (18.8 min) and more fluoroscopy usage (16 shots) compared to cESI group with mean procedure time of 13 min (P = 0.014) and fluoroscopy usage of 10 shots (P = 0.023), respectively. No major adverse events were reported for either of the groups. Conclusion: cESI is a simple, safe, and efficacious technique comparable to tf ESI in the management of unilateral L5-S1 paracentral discogenic radicular pain with significantly less procedural time and fluoroscopy usage. Further, large-scale studies are needed to validate the study results.