The effectiveness of repeat lumbar transforaminal epidural steroid injections

Objective: The aim of this study was to determine 1) if repeat lumbar transforaminal epidural steroid injections (TFESIs) resulted in recovery of pain relief, which has waned since an index injection, and 2) if cumulative benefit could be achieved by repeat injections within 3 months of the index injection. Design: Retrospective observational study with statistical modeling of the response to repeat TFESI. Setting: Academic radiology practice. Patients: Two thousand eighty-seven single-level TFESIs were performed for radicular pain on 933 subjects. Subjects received repeat TFESIs >2 weeks and <1 year from the index injection. Methods: Hierarchical linear modeling was performed to evaluate changes in continuous and categorical pain relief outcomes after repeat TFESI. Subgroup analyses were performed on patients with <3 months duration of pain (acute pain), patients receiving repeat injections within 3 months (clustered injections), and in patients with both acute pain and clustered injections. Results: Repeat TFESIs achieved pain relief in both continuous and categorical outcomes. Relative to the index injection, there was a minimal but statistically significant decrease in pain relief in modeled continuous outcome measures with subsequent injections. Acute pain patients recovered all prior benefit with a statistically significant cumulative benefit. Patients receiving clustered injections achieved statistically significant cumulative benefit, of greater magnitude in acute pain patients. Conclusion: Repeat TFESI may be performed for recurrence of radicular pain with the expectation of recovery of most or all previously achieved benefit; acute pain patients will likely recover all prior benefit. Repeat TFESIs within 3 months of the index injection can provide cumulative benefit.