Pain reduction after lumbar epidural injections using particulate versus non-particulate steroids: intensity of the baseline pain matters

Objectives To compare pain relief after CT-guided lumbar epidural steroid injections (ESI) using particulate (triamcinolone) and non-particulate (dexamethasone) steroids, and to explore factors affecting the effectiveness of both steroid types. Methods This retrospective observational study included 806 patients with lumbar radiculopathy and corresponding MRI or CT abnormalities of the lumbar spine, who were matched using the propensity score method, yielding two cohorts of 209 patients each. Pain intensity was evaluated prior to the procedure using a pain numerical rating scale (NRS) with range 0–10. Reevaluation took place 1 day and 4 weeks post-injection. Logistic regression analysis and cubic splines applied to generalized additive models were implemented to assess the differences in pain reduction after ESI in the analyzed patient groups. Results Four weeks post-injection, the overall chance of ≥ 50% pain reduction was lower in the dexamethasone group than that in the triamcinolone group (odds ratio [OR] = 0.55; p < 0.012). In the dexamethasone cohort, the intensity of baseline pain and the presence of a herniated intervertebral disc in the infiltrated segment were both significant and independent predictors of ≥ 50% pain relief. Patients with baseline NRS score ≥ 7 points had markedly less chance of ≥ 50% pain relief than patients with NRS score < 7 (OR = 0.53; p < 0.032), whereas disc herniation increased the chances more than twofold (OR = 2.29; p < 0.044). There was no significant correlation between the effectiveness of triamcinolone and any analyzed concomitant variables. Conclusions Triamcinolone was superior for lumbar radiculopathy of severe intensity. For mild to moderate pain, no benefit of using triamcinolone over dexamethasone was found. The effectiveness of dexamethasone was lower for stenotic spinal lesions than for disc herniation