Epidural Contrast Flow Patterns of Transforaminal Epidural Steroid Injections Stratified by Commonly Used Final Needle-Tip Position

Objective. To evaluate the relationship between commonly used final needle-tip positions and subsequent contrast flow and patient-reported pain relief in transforaminal epidural steroid injections (TFESIs). Design. Retrospective cross-sectional study. Methods. Medical records of subjects (N = 83) having undergone a TFESI between January 2008 and January 2009 were reviewed to compare TFESIs using the superior-anterior (SA) vs. the superior-posterior (SP) quadrant. Outcome Measures. Outcome measures included ventral and dorsal epidural contrast flow as well as near-to-complete pain relief as measured by numerical rating scale pain score pre- and post-procedure. Results. SA TFESIs were associated with greater ventral epidural contrast flow as compared with SP TFESIs (100% vs 61.4%, P < 0.001). SA TFESIs with ventral epidural contrast flow were also associated with flow to a greater number of vertebral levels than SP TFESIs with ventral epidural contrast flow (41% vs 14.8%, P < 0.001). SP TFESIs were associated with greater dorsal epidural contrast flow than SA TFESIs (95.5% vs 43.6%, P < 0.05). SA TFESIs were also associated with a larger proportion of patients who achieved near-to-complete pain relief (P < 0.05) and greater reduction than SP TFESIs in post-procedure pain score relative to pre-procedure (3.3 vs 1.5, P < 0.01). Discussion. The evolution of TFESIs must balance both safety and efficacy. The efficacy of SA TFESIs is demonstrated to be superior to that of SP TFESIs with regards to ventral epidural flow and patient-reported pain relief. Further efforts should focus on demonstrating efficacy while optimizing safety.