A Randomized Controlled Clinical Trial to Determine the Effectiveness of Caudal Epidural Steroid Injection in Lumbosacral Sciatica

Introduction: Caudal epidural steroid injection have been a part of nonsurgical management of lumbosacral sciatica since last half a century but various randomized controlled trials fail to provide convincing evidence in favour of its effectiveness.

Aim: To assess the efficacy of caudal epidural steroid injection in patients of lumbosacral sciatica in comparison to placebo.

Materials and methods: The study consisted of patients of sciatica caused by lumbosacral disc prolapse (observed on Magnetic Resonance Imaging (MRI) scan). Caudal epidural injections of 80 mg methyl prednisolone were injected in 47 patients in one group. The other group consisted of 46 patients who were injected isotonic saline as placebo. Self-evaluation was the main judgment criterion at 4^th week using a descriptive four item scale (recovery, marked improvement, slight improvement, or worse). Patients rating the improvement as "recovery" or "marked improvement" were considered as success. Patients rating the improvement as "slight improvement" or "worse" were considered as failure. Only paracetamol were authorized and patients requiring Non Steroidal Anti-inflammatory Drugs (NSAIDs) before 4^th week were also considered as failure.

Results: On analysis per protocol, at 4 weeks, the two groups differed significantly with respect to the primary outcome: among the 93 patients, 8/46 (17%) in the placebo group and 32/47 (68%) in the steroid group (p=0.000) were considered as success (difference 50.7%; 95% CI for the difference 33.4 to 67.99). But at the end of the study (week 12) there was no significant difference in primary outcome between the groups: 22/46 (48%) patients in the placebo group and 28/47 (60%) in the steroid group (p=0.25) were considered as success (difference 11.8%; 95% CI for the difference -8.38 to 31.9).

Conclusion: Caudal epidural steroid injections provide no additional improvement over placebo in the long term natural history of lumbosacral sciatica. However, it can be an important component of short term management of painful sciatica.