Current versus revised anatomical targets for genicular nerve blockade and radiofrequency ablation: evidence from a cadaveric model

Abstract

Introduction: Recent studies have proposed revised anatomical targets to improve accuracy of genicular nerve (GN) radiofrequency ablation (RFA). This study aims to compare the accuracy of classical and revised techniques for fluoroscopic-guided GN-RFA in cadaveric models.

Materials and methods: Fourteen knees from seven fresh frozen human cadavers were included in this study. For each cadaver, RF cannulas were placed to capture the GN according to the current targets in one knee, and the revised targets in the other knee, randomly. The stylet was removed from the cannula, plunged into non-diffusible black paint, and reintroduced entirely in the cannula, to create a limited black spot on the tissues at the top of the active tip. Anatomical dissection was performed, and the accuracy of both techniques was compared.

Results: The mean distance from the top of the active tip to the nerve was significantly lower with revised than current targets for the superior-medial GN (0.7 mm vs 17.8 mm, p=0.01) and the descending branch of the superior-lateral GN (3.7 mm vs 24.4 mm, p=0.02). In both superior-medial GN and superior-lateral GN, the accuracy rate was higher with revised than current targets: 100% vs 0% and 64% vs 35%, respectively. In addition, the accuracy of revised targets for the recurrent fibular nerve and the infrapatellar branch of saphenous nerve was 100%.

Conclusion: This study demonstrates that the revised targets are more accurate than the current targets for GN-RFA.

Keywords: anatomy; pain medicine; radiofrequency ablation.