The Effect of Skin Pressure on Needle Entry Point Accuracy During Fluoroscopically Guided Lumbar Transforaminal Epidural Injections: A Randomized Clinical Trial.

OBJECTIVE: The aim of this study was to investigate the effect of skin pressure on needle entry point accuracy during fluoroscopically guided lumbar transforaminal epidural injection.

DESIGN: This study is a prospective randomized clinical trial; 64 patients with a body mass index of 25 kg/m or greater were enrolled. For patients in the pressing group, the operator marked the needle entry point on the patient's back while pressing the patient's skin with the tip of an indicator. For patients in the nonpressing group, the tip of the indicator was gently positioned on the patient's skin. The data related to technical performance and radiation exposure during the procedure were compared.

RESULTS: Sixty patients (nonpressing group, n = 30; pressing group, n = 30) were analyzed. There were more attempts to reposition the needle (n) and increased procedure time (in seconds) in the pressing group (median, 5 vs. 4 [P = 0.019]; 400.0 vs. 358.5 [P = 0.033]). The fluoroscopy time (in seconds) and the kerma-area product (in cGy cm) were also significantly longer and greater in the pressing group, respectively (median, 63.5 vs. 50.5 [P = 0.038]; 416.3 vs. 318.6 [P = 0.014]).

CONCLUSIONS: This study shows that practitioners should not press the skin with a radiopaque indicator when determining the needle entry point by fluoroscopy during lumbar transforaminal epidural injection.