The effect of cervical parameters on interlaminar epidural steroid injection treatment outcomes in patients with cervical disc herniation.

Objectives: The aim of this study was to investigate the effect of cervical alignment parameters on outcomes of fluoroscopy-guided cervical interlaminar epidural steroid injection. Patients and methods: This prospective observational clinical study included 63 patients (40 females, 23 males; mean age: 45.3±9.4 years; range, 24 to 69) with radicular pain due to central/paracentral cervical disc herniation between June 2022 and April 2023. Cervical anteroposterior, lateral, and oblique radiographs were taken before the procedure. The C7 slope, spinocranial angle (SCA), and cervical sagittal vertical axis (cSVA) were measured. Pain intensity was assessed using the Numerical Rating Scale (NRS) before and at three weeks and three months after the procedure. The disability and quality of life were evaluated with the Neck Disability Index (NDI) and the 12-item Short-Form Heath Survey (SF-12). Results: Considering the outcomes at the three-month follow-up, there were moderate positive correlations between SCA and the improved NRS and NDI scores. Moderate negative correlations were determined between C7 slope and the improved NRS and NDI scores. There were also moderate negative correlations between cSVA and the improved NRS and NDI scores. Regarding the improvement in the physical component summary of SF-12, there was a moderate negative correlation with the C7 slope, a weak negative correlation with the cSVA, and a weak positive correlation with the SCA. The improved mental component summary of SF-12 was weakly positively correlated with SCA and weakly negatively correlated with C7 slope and cSVA. Conclusion: The C7 slope, cSVA, and SCA are cervical alignment parameters affecting the success of cervical interlaminar epidural steroid injection treatment.