Modification of the Cervical Transforaminal Epidural Steroid Injection Technique Based Upon the Anatomic Angle of the Superior Articular Process on MRI.

Abstract

A modification of the conventional technique for cervical transforaminal epidural steroid injection (CTFESI) has been developed. This technique may, theoretically, decrease the likelihood of the needle encountering the vertebral artery and spinal nerve. The approach uses angle measurements of the superior articular process ventral surface from the patient's axial MRI as a guide for fluoroscopic set-up and needle trajectory. This report aims to compare contrast flow patterns of the modified approach with those of the conventional technique. Retrospective chart review and prospective blinded analysis of contrast flow patterns. Setting. Outpatient interventional physiatry practice. A retrospective blinded qualitative review of fluoroscopic images was performed to compare contrast flow patterns of CTFESIs performed using the modified approach with those using the conventional technique. A detailed description of the modified approach is provided in this report. Ninety-seven CTFESI procedures were used for flow analysis. The modified approach resulted in a statistically significant greater percentage of injections with epidural flow: 69% [95% CI = 57-82%] modified approach vs. 42% [95% CI = 28-56%] conventional approach. The modified technique also showed a statistically significant higher percent of injections categorized as having an ideal flow pattern, that of predominate epidural and/or intraforaminal flow: 65% [95% CI = 52-78%] vs. 27% [95% CI = 14-40%]. A modification of the conventional CTFESI technique, developed for the purpose of improved safety, may provide superior contrast flow patterns when compared to the conventional approach.