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

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.