Study design: A randomized, double-blind controlled trial.
Objectives: To determine the treatment effect of corticosteroids in periradicular infiltration for chronic radicular pain. We also examined prognostic factors in relation to the outcome of the procedure.
Summary of background data: Various studies have examined the therapeutic value of periradicular infiltration using treatment agents consisting of local anesthetic and corticosteroids for radicular pain, secondary to lumbar disc herniation and spinal stenosis. There is currently no randomized trial to determine the efficacy of a single injection of corticosteroids for chronic radicular pain.
Methods: Eligible patients with radicular pain who had unilateral symptoms who failed conservative management were randomized for a single injection with bupivacaine and methylprednisolone or bupivacaine only. Outcome measures included the Oswestry Disability Index, visual analogue score for back pain and leg pain, claudication walking distance, and the patient's subjective level of satisfaction of the outcome.
Results: We recruited 43 patients in the bupivacaine and methylprednisolone group and 43 patients in the bupivacaine only group. The follow-up rate is 100%. Five patients had early termination of the trial for discectomy and further root block. There is no statistically significant difference in the outcome measures between the groups at 3 months (change of the Oswestry Disability Index [P = 0.68], change in visual analogue score [back pain, P = 0.68; leg pain, P = 0.94], change in walking distance [P = 0.7]). Duration of symptoms has a statistically significant negative association with the change in Oswestry Disability Index (P = 0.03).
Conclusion: Clinical improvement occurred in both groups of patients. Corticosteroids did not provide additional benefit.