METHODS: This was a prospective, randomized clinical study and blind to the evaluators. Will include 20 patients with knee osteoarthritis grade III or IV, refractory to medical treatment. A group will be submitted to neurotomy by radiofrequency of genicular nerves guided by fluoroscopy and the other group will receive neurotomy by radiofrequency of saphenous nerve, guided by ultrasound. They will be assessed in pain intensity at rest and movement, functionality, satisfaction and adverse effects related to treatment. Patients will be evaluated 15 days, 1 month, 3, 6 and 12 months after the procedure.