Endoscopic Pulsed Radiofrequency Ablation of Genicular Nerves for the Treatment of Chronic Knee Pain

Abstract

Chronic knee pain is the second most common cause of chronic pain in the United States. Occasionally, patients become refractory to conventional treatments such as intraarticular cortisone injections and viscosupplementation. Patients who have exhausted these therapies or have a contraindication to the therapies may be candidates for diagnostic genicular nerve block and if successful, subsequent radiofrequency ablation (RFA). For patients who have undergone image-guided genicular nerve radiofrequency ablation with fluoroscopic or ultrasound guidance without success, an endoscopic approach can be used as an alternative modality with success. With direct visualization of the genicular nerves, the likelihood of success with an endoscopic approach increases as some patients can have varying anatomy of the genicular nerves for which cannot always be detected with fluoroscopy or ultrasound. The purpose of this study is to demonstrate the utilization of a direct endoscopic approach for genicular nerve RFA for patients with chronic knee pain that have failed to improve after image-guided genicular RFA with fluoroscopic or ultrasound guidance. Two patients who had underwent successful diagnostic genicular nerve blocks were assessed for pre-procedure and post-procedure visual analog scale (VAS) scores following endoscopic genicular nerve RFA after failure of the conventional image guided approach at 6 and 12 months. Both patients reported greater than 80% reduction in VAS score and improvement in function at 6 and 12 months Limitations of the current study is a limited number of patients, and lack of the use of a formal functional scale to demonstrate improvement. Ultimately, the conclusion was drawn that an endoscopically-guided genicular nerve RFA can be utilized successfully due to direct visualization of the genicular nerves when conventional approaches with Fluoroscopic/ultrasound guidance has failed to achieve analgesia and functional improvement. Key words: Genicular nerve block, endoscopic, radiofrequency ablation. knee pain, chronic osteoarthritis, genicular neuritis, genicular neuralgia, total knee arthroplasty, arthritis