Genicular Nerve Radiofrequency Ablation for Painful Knee Arthritis: The Why and the How

Genicular nerve radiofrequency ablation (GNRFA), including conventional, cooled, and pulsed techniques, has been used in the management of symptomatic knee osteoarthritis (OA). This new and innovative treatment option has the capacity to decrease pain and improve function and quality of life in certain patients. GNRFA is reserved for patients with symptomatic knee OA who have had failure of conservative treatment and have had failure of or are poor candidates for surgery. GNRFA has been shown to consistently provide short-term (3 to 6-month), and sometimes longer, pain relief in patients. GNRFA has been demonstrated to be safe to administer repeatedly in patients who respond well to this minimally invasive procedure. GNRFA is a 2-step procedure. First, patients are given a diagnostic block under fluoroscopy or ultrasound guidance. Specifically, 1 mL of lidocaine is injected using a 20-gauge, 3.5-in (8.9-cm) spinal needle around the superior lateral, superior medial, and inferior medial genicular nerve branches. The diagnostic block is extra-articular. If the patient reports a ≥50% reduction in baseline pain for a minimum of 24 hours following the injection, then the patient is a candidate for genicular ablation. The osseous landmarks for the diagnostic block are exactly the same as for the ablation procedure. Both procedures are well tolerated in the office setting under local skin anesthesia or can be done in the operating room under conscious sedation using a low-dose sedative such as midazolam for anxious patients. General anesthesia is not required for GNRFA. This procedure is most commonly performed by interventional pain specialists but may also be performed by any physician with appropriate training. In some jurisdictions, physician assistants and nurse practitioners may perform this procedure subject to their supervision requirements. Conservative treatment for symptomatic knee OA includes weight loss management, physical and aquatic therapy, bracing, lateral wedge insoles, transcutaneous nerve stimulation, nonsteroidal anti-inflammatory drugs in combination with a proton pump inhibitor, autologous blood-based therapies, and cortisone and hyaluronic acid injections . Surgical treatment for symptomatic knee OA includes knee arthroscopy, high tibial osteotomy, total knee replacement, and unicompartmental knee replacement in patients without lateral compartment disease . It should be noted that there is some evidence suggesting that steroid injection,