Pulsed Radiofrequency of the Composite Nerve Supply to the Knee Joint as a New Technique for Relieving Osteoarthritic Pain: A Preliminary Report

We report a new technique for pulsed radiofrequency (PRF) of the entire nerve supplyof the knee as an option in treating osteoarthritis (OA) of knee. We targeted bothsensory and motor nerves supplying all the structures around the knee: joint, muscles,and skin to address the entire nociception and stiffness leading to peripheral and centralsensitization in osteoarthritis. Ten patients with pain, stiffness, and loss of function inboth knees were treated with ultrasonography (USG) guided PRF of saphenous, tibial,and common peroneal nerves along with subsartorial, peripatellar, and popliteal plexuses.USG guided PRF of the femoral nerve was also done to address the innervation of thequadriceps muscle. Assessment of pain (Numerical Rating Scale [NRS], pain DETECT, kneefunction [Western Ontario and McMaster Universities Osteoarthritis Index- WOMAC])were documented pre and post PRF at 3 and 6 months. Knee radiographs (KellgrenLawrence [K-L] grading) were done before PRF and one week later. All the patients showeda sustained improvement of NRS, pain DETECT, and WOMAC at 3 and 6 months. Thesignificant improvement of patellar position and tibio-femoral joint space was concordantwith the patient’s reporting of improvement in stiffness and pain. The sustained pain reliefand muscle relaxation enabled the patients to optimize physiotherapy thereby improvingendurance training to include the daily activities of life. We conclude that OA knee pain isa product of neuromyopathy and that PRF of the sensory and motor nerves appeared tobe a safe, effective, and minimally invasive technique. The reduction of pain and stiffnessimproved the knee function and probably reduced the peripheral and central sensitization.Key words: Osteoarthritis, knee pain, stiffness, knee innervation, femoral nerve supply,Hilton’s law, peripheral sensitization, pulsed radiofrequency treatment of nerves to kneejoint