Efficacy of Corticosteroid Addition to Selective Nerve Root Block for Lumbar Radiculopathy: A Multicenter Prospective Cohort Study.

INTRODUCTION

The addition of corticosteroids to selective nerve root block (SNRB) is widely practiced for lumbar radiculopathy, yet robust evidence regarding its efficacy for functional outcomes remains limited. We evaluated whether adding corticosteroids to local anesthetic in SNRB relieves functional disability and improves quality of life in patients with lumbar radiculopathy.

METHODS

This multicenter, prospective cohort study enrolled 78 patients with single-level lumbar radiculopathy. Patients received fluoroscopy-guided SNRB with either corticosteroids (dexamethasone, betamethasone) plus 1% lidocaine (n=64) or lidocaine alone (n=14). The primary outcome was the Oswestry Disability Index (ODI) at 90 and 180 days. Secondary outcomes included visual analog scale (VAS) scores for leg pain, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), and minimal clinically important difference (MCID) achievement rates. Linear mixed-effects models were used for analysis.

RESULTS

The steroid group indicated significantly greater ODI improvement at 90 days (27.9 vs 47.1; mean difference, 19.2 points [95% confidence interval (CI), 6.8-31.6]; p=0.002) and 180 days (29.0 vs 44.1; mean difference, 15.1 points [95% CI, 2.3-27.9]; p=0.022), with large effect sizes (Cohen d>0.8). Significant improvements favoring corticosteroids were observed for VAS scores at 90 days (3.5 vs 5.7; p=0.018) and 180 days (3.7 vs 5.9; p=0.023) and multiple JOABPEQ domains. MCID achievement was significantly higher in the steroid group at 90 days (75.0% vs 33.3%; p=0.043); the number needed to treat was 2.4. Adverse event rates were similar in the groups, and no serious adverse events occurred. Benefits plateaued between 90 and 180 days.

CONCLUSIONS

Adding non-particulate corticosteroids to SNRB significantly relieved functional disability and pain and improved quality of life in patients with lumbar radiculopathy, with the most pronounced group differences occurring at 90 days and sustained through 180 days. Clinically, the 90-day timepoint is optimal for evaluating treatment success and determining the need for alternative treatments.