Comparative analysis of contrast distribution in cervical epidural steroid injections utilizing a modified paramedian interlaminar approach with varied needle tip positions: A randomized controlled trial

Background: Recent advancements in cervical interlaminar epidural steroid injections have given rise to the modified paramedian interlaminar (mPIL) approach. The objective of this study was to perform an analysis of the contrast spread pattern within the cervical epidural space, taking into account different needle tip positions in the mPIL approach. Methods: A total of 48 patients were included in the study and randomly assigned to either the medial or lateral group based on the needle tip's position in the anterior–posterior view. The primary outcome measured was the contrast flow under fluoroscopic visualization. As a secondary outcome, we analyzed the location of the needle tip position in both lateral and contralateral oblique views. Clinical effectiveness was assessed by measuring pain intensity and functional disability post-procedure. Results: Significant disparities were noted in the ventral distribution of contrast between the medial and lateral groups. In the lateral images, needle tips in the lateral group were positioned more ventrally compared to those in the medial group. Both groups exhibited statistically significant improvements in neck and radicular pain, as well as functional status, 4 weeks after treatment, with no significant differences between them. Conclusions: Our results suggest that the ventral dispersion of contrast material during cervical interlaminar epidural steroid injections using the mPIL approach may vary depending on the needle tip location.