No Efficacy of Dexamethasone Injections for Acute Sciatica: A Double-Blind Randomized Study Versus Saline.

Abstract

BACKGROUND: The efficacy of caudal injections for patients with acute sciatica remains controversial. The DEXHIA study was designed to evaluate whether ultrasound-guided caudal injection of dexamethasone provides superior clinical outcomes compared with saline placebo. METHODS: This prospective, randomized, placebo-controlled, double-blind trial included adult patients with sciatica secondary to lumbar disc herniation of less than 3 months' duration. Participants were randomly assigned in a 1:1 ratio to receive either 16 mg of dexamethasone (4 mL) diluted with 16 mL of saline (DEXA group) or 20 mL of saline alone (PLACEBO group), administered by ultrasound-guided caudal epidural injection. The primary outcome was the change in the Oswestry Disability Index (ODI) at 3 weeks. Secondary outcomes included leg pain and low back pain assessed by visual analogue scale (VAS), health-related quality of life (SF-36), need for repeat epidural injection, and need for lumbar surgery. Clinical assessments were performed at 3 weeks, 3 months, and 6 months. RESULTS: A total of 106 patients were randomized, with 53 participants assigned to each treatment group. The primary endpoint was not met, as the improvement in ODI at 3 weeks did not differ significantly between groups (mean change: -9.5 ± 4.4 in the DEXA group versus -13.8 ± 4.4 in the PLACEBO group; p = 0.18). No significant differences were observed for any relevant secondary outcome at any follow-up time point. During the 6-month follow-up, 34 patients in the DEXA group and 30 patients in the PLACEBO group underwent a second, non-blinded injection of dexamethasone (ns). Lumbar surgery was performed in 10 patients in the DEXA group and nine patients in the PLACEBO group (ns). Injection-related adverse events were mild and transient but occurred more frequently in the DEXA group. CONCLUSIONS: Caudal injection of soluble dexamethasone conferred no clinical benefit over saline placebo in patients with acute sciatica. SIGNIFICANCE STATEMENT: Epidural injections are widely used worldwide for the treatment of resistant sciatica and have been extensively studied in multiple meta-analyses. However, their clinical value remains debated due to the limited methodological quality of most available studies. We conducted a methodologically rigorous randomized, placebo-controlled trial, which yielded negative results. These findings question the efficacy of caudal epidural injection of a non-particulate corticosteroid administered via a remote (sacrococcygeal) approach for disc-related sciatica. TRIAL REGISTRATION: The trial was registered under European Clinical Trials No. 2021-001571-17 and ClinicalTrials.gov identifier NCT05000658.