Factors Associated with Treatment Success After Interlaminar Epidural Steroid Injection for Cervical Radicular Pain

AIM: To investigate the demographic, clinical and radiological findings associated with treatment success after interlaminar epidural steroid injection (ILESI) in radicular pain induced by cervical disc herniation. MATERIAL and METHODS: In this retrospective study, the data of patients who received cervical ILESI between January 2017 and June 2021 were screened. Of 223 patients, 92 with unilateral radicular neck pain due to cervical disc herniation were included. Demographic data, symptom duration, and numerical rating scale scores at baseline, at three weeks, three months, and six months after treatment were collected from the medical records of the patients. Disc herniation level, cervical axis, disc height, presence and degree of spinal canal and neural foraminal stenosis, vertebral endplate signal change, and definitive presence of uncovertebral and facet osteoarthritis were evaluated using cervical spine magnetic resonance imaging. Treatment success was determined as >= 50% reduction in pain scores at six months compared to baseline. RESULTS: Data of 92 patients (27 men, 65 women) were included. The mean age was 50.82 +/- 10.22 years, and the median symptom duration was 12 (4.25 to 20) months. At six months after ILESI, treatment was successful in 58 (58.7%) patients and unsuccessful in 34 (41.3%) patients. Multivariable logistic regression analysis was performed to identify the factors associated with treatment success at six months post-injection. In the final model, neural foraminal stenosis (non-severe vs. severe) and spinal canal stenosis (non-severe vs. severe) were significantly associated with the treatment success (OR=3.02, 95% CI=1.40-10.95, p=0.009; CONCLUSION: Treatment success of cervical ILESI at six months is favorable. However, the presence of severe neural foraminal and spinal canal stenosis is associated with a reduced likelihood of treatment success.