Randomized Double-Blind Controlled Trial Comparing the Effectiveness of Lumbar Transforaminal Epidural Injections of Particulate and Nonparticulate Corticosteroids for Lumbosacral Radicular Pain

Abstract

Objective: To compare equivalent doses of a nonparticulate (dexamethasone) with a particulate (betamethasone) corticosteroid in lumbar transforaminal epidural steroid injections (TFESIs) in terms of pain, function, and complications.

Design: Fifty-six patients presenting with debilitating radicular pain were randomized in a double-blind controlled trial to receive a lumbar transforaminal injection of either dexamethasone 7.5 mg (n = 29) or betamethasone 6.0 mg (n = 27).

Setting: A pain clinic and physical medicine and rehabilitation department in two academic hospital centres.

Outcome measures: Data were collected at 1-, 3-, and 6-month follow-ups. The primary outcome was pain reduction on a visual analog scale (VAS) at 3 months. Secondary outcomes were functional improvement, as measured by the Oswestry Disability Index (ODI), and number and type of complications.

Results: No differences on the VAS, analyzed either as a continuous (P = 0.209) or categorical variable (≥50% (P = 0.058) or ≥75% (P = 0.865) improvement) and ODI (P = 0.181) were found between the two groups at 3 months. At 6 months, improvement of ODI score was at the limit of statistical significance in favor of dexamethasone (P = 0.050). Multivariate regression analysis, adjusting for potential confounding variables, showed that differences on the ODI became statistically significant at the 6 month follow-up, also in favor of dexamethasone (adjusted P = 0.003). No serious complications were observed in either group.

Conclusion: According to this study, pain relief and functional improvement are similar for both dexamethasone and betamethasone at 3 months. Considering its safety profile, dexamethasone could be considered as first choice for TFESI. However, given that the study was underpowered, more research is needed to support a recommendation of systematically using dexamethasone in TFESI.

Keywords: Betamethasone; Dexamethasone; Lower Limb Pain; Nonparticulate and Particulate Steroids; Transforaminal Epidural Injection.