Ten Years of Lumbar Transforaminal Epidural Steroid Injections in a Tertiary Referral Center: Trends in Clinical Indications and Outcomes

INTRODUCTION: Transforaminal epidural steroid injection (TFESI) is commonly applied for lumbar radicular pain. High-level evidence supports the use in disc-related radiculopathy, while evidence for TFESI in neuroforaminal stenosis remains consensus-based. METHODS: A retrospective repeated cross-sectional study was conducted covering January 2013-December 2022. The dataset comprised 11,208 unique patients reimbursed for TFESI. Trends in clinical indications were analyzed using automated keyword-based text recognition. Representative cohorts from 2014 (n = 266) and 2022 (n = 299) were randomly selected for clinical and radiologic reviews. Imaging was reassessed according to established grading systems. Pain intensity and global perceived effect were evaluated approximately 6 weeks post-injection. Parametric and non-parametric statistics, linear regression, and ordinal logistic regression were applied. A two-sided p < 0.05 was considered statistically significant. RESULTS: Mean patient age and the proportion of stenosis-related indications both increased steadily between 2013 and 2022 (p < 0.001). In the studied cohorts, short-term pain decreased significantly after TFESI across all phenotypical subcategories, except for moderate-to-severe central canal compression in 2014. Neuroforaminal stenosis predicted greater pain improvement regardless of its nature in 2014 (p = 0.006), whereas disco-osteophyte abnormalities and chronic or recurrent symptoms were associated with less pain reduction in 2022 (p < 0.05). Female patients showed less short-term improvement than males. At one-year follow-up, central canal stenosis predicted a lower likelihood of being pain-free (OR = 0.63, p = 0.022). CONCLUSIONS: This retrospective study found an upward trend in patient age and a growing proportion of non-discogenic neuroforaminal stenosis as indications for TFESI. While modest short-term pain reduction was observed, outcomes were slightly negatively influenced by central compression, disco-osteophyte abnormalities, chronic symptoms, and female sex.