Effectiveness of transforaminal epidural steroid injection by using a preganglionic approach: a prospective randomized controlled study.

PURPOSE To prospectively evaluate the short- and midterm effectiveness of transforaminal epidural steroid injection (TFESI) for lumbosacral radiculopathy with respect to injection level. MATERIALS AND METHODS Institutional review board approval and written informed consent were obtained. From March 2005 to February 2006, 239 consecutive patients (106 male, 133 female; mean age, 49.8 years; range, 13-82 years) who were scheduled to undergo lumbar TFESI were enrolled. The patients were randomly assigned to either the ganglionic (TFESI at the location of the exiting nerve root) or preganglionic group (TFESI at the supraadjacent intervertebral disk level). Follow-up was conducted within 1 month (short term) and more than 6 months (midterm) after injections. Short- and midterm outcomes were measured by using a visual analog scale and a four-grade scale. Univariate analysis (by using the Fisher exact and chi(2) tests) and multiple logistic regression analysis were performed to evaluate the relationship between possible outcome predictors (ganglionic or preganglionic injection levels, cause of radiculopathy, duration of symptoms, age group, and sex) and the therapeutic effect. RESULTS Univariate analysis showed that the preganglionic group had a better treatment effect (99 of 112, 88.4%) than did the ganglionic group (90 of 127, 70.9%) at short-term follow-up (P = .001). Multiple logistic regression analysis showed that the only significant outcome predictor at short-term follow-up was injection level (odds ratio = 2.232, P = .037). No significant difference was identified regarding TFESI approach or cause of radiculopathy at midterm follow-up. CONCLUSION TFESI for lumbosacral radiculopathy with a preganglionic approach is more effective than TFESI with a ganglionic approach at short-term follow-up.