Ultrasonography- and Fluoroscopy-Guided Technique for Cooled Radiofrequency Ablation of the Genicular Nerves for Knee Joint Pain

Background: Knee osteoarthritis is a chronic degenerative disease associated with pain and decreased mobility that affects advanced-age individuals, thus causing further debilitation. Radiofrequency ablation can benefit patients who are not ideal candidates for surgical intervention and for whom conservative management has been unsatisfactory. Currently, radiofrequency ablation is performed using either ultrasonography or fluoroscopy. In this technique review, we propose a method of performing cooled radiofrequency ablation of the genicular nerves that uses both ultrasonography and fluoroscopy and that could be helpful for novice pain practitioners. Case Series: We report the experience of 2 patients with grade 4 osteoarthritis knee joints who underwent our cooled radiofrequency ablation technique. Each patient received a diagnostic block using ultrasonography, with ≥70% pain relief the prerequisite for performing cooled radiofrequency ablation. Our radiofrequency ablation technique involves using ultrasonography to identify and mark the superomedial, superolateral, and inferomedial genicular arteries. The marking done with ultrasonography is used during needle insertion with fluoroscopy guidance to reach the target points, and the final position of the needle is confirmed using sensory and motor stimulation before the cooled radiofrequency ablation procedure is performed. The cooled radiofrequency ablation resulted in pain reduction as measured on the visual analog scale and the Western Ontario and McMaster Universities Osteoarthritis Index scores at both patients' 3- and 6-month follow-ups. Conclusion: Using this technique for cooled radiofrequency ablation of the genicular nerves might help to reduce radiation exposure, specifically when the procedure is being performed by novice practitioners with limited experience.