Figure. Anteroposterior radiograph of bilateral knees.
A 76-year-old woman with a history of chronic right knee pain due to arthritis presents for evaluation. She has received intra-articular steroid injections for years, but the injections are no longer effective. She is not a surgical candidate for a total knee replacement due to severe cardiovascular disease. An anteroposterior radiograph of her knees is obtained (Figure). The patient asks about a procedure that “burns” the nerve roots to provide pain relief.
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Osteoarthritis of the knee is one of the most common conditions seen in orthopedic practice. In rare instances, conservative treatments fail to provide relief and the patient is not a candidate for total joint replacement due to factors such as obesity, poor health, or wishes to avoid surgery. For these patients, ablation of the genicular nerves that account for pain reception in the knee joint has proven to be an effective treatment option.1
Under fluoroscopy, the superior medial, superior lateral, and the inferior medial genicular nerves are ablated with a radiofrequency electrode that reaches temperatures of 80 °C for 1 minute.1 Ablation causes damage to the nerve structures, which blocks pain transmission to the central nervous system.
Geniculate nerve radiofrequency ablation (GNRFA) has been shown to relieve knee pain for at least 6 months.2 Pain returns as the nerve structures are again restored.
The procedure can also be used in patients who continue to have pain after a total knee replacement despite any identifiable cause such as infection, hardware that is incorrectly positioned, or other obvious causes.1
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
1. Kidd VD. Genicular nerve radiofrequency ablation. JBJS Journal of Orthopaedics for Physician Assistants. 2018;6(1):e10.
2. Chen AF, Khalouf F, Zora K, et al. Cooled radiofrequency ablation compared with a single injection of hyaluronic acid for chronic knee pain: a multicenter, randomized clinical trial demonstrating greater efficacy and equivalent safety for cooled radiofrequency ablation. J Bone Joint Surg Am. 2020;102(17):1501-1510.