Does a Positive Response to Transforaminal Epidural Steroid Injection Identify Patients Who Can Avoid Surgery for Two Years?

Abstract

Background. Transforaminal epidural steroid injection (TFESI) is widely used to manage lumbar radiculopathy. In clinical settings, patients often undergo repeated transforaminal epidural injections with or without steroid administration. Objectives. To examine whether a positive response to TFESI at the first month, can in clinical settings, identify patients with radiculopathy who can avoid surgery for two years. Study Design/Setting. This prospective observational study was conducted at an academic medical center. Methods. Individuals aged ≥20 years who had been referred to our pain center by spine surgeons were enrolled. All patients were assessed using the Numerical Rating Scale (NRS) at baseline and 1 month after the first TFESI. Patients were divided into two groups according to the NRS decrement: the positive response (PR) group achieved a ≥2.0 decrease on the NRS 1 month after the first TFESI compared to baseline and the no response (NR) group achieved a <2.0 decrease on the NRS. The incidence rates of surgery over two years were compared between the two groups. In addition, we calculated the hazard ratio of the PR group to the NR group regarding the incidence of surgery over two years using the Cox proportional hazard model, adjusting for baseline NRS. Results. Seventy-six patients completed the two-year follow-up. In total, 8 and 68 patients had bilateral and unilateral radiculopathy, respectively. The PR and NR groups included 35 and 41 patients, respectively. The rate of surgery avoidance was 85.7% and 73.2% in the PR and NR groups, respectively. This difference was not statistically significant ( $p=0.26$ ). After adjusting for baseline NRS, the hazard ratio of the PR group to the NR group regarding the incidence of surgery within two years was 0.35 (95% confidence interval: 0.11–1.11, $p=0.08$ ). Conclusion. A positive response to TFESI may not identify patients who can avoid surgery for two years.