Comparative Study Between Eight Versus Three Genicular Nerves Radiofrequency Ablation for Knee Denervation in Advanced Knee Osteoarthritis Using Ultrasound

Knee pain is a common issue in adults, with a steadily increasing prevalence (1). There are many causes of knee pain, such as meniscal and tendon injuries, posttraumatic syndrome, and postsurgical pain; osteoarthritis is the leading cause (2).

Knee osteoarthrosis (KOA) is a very common joint disease, with a prevalence ranging from 4.2% to 15.5% and gradually increasing with age (3). It is associated with diverse causes including age, obesity, metabolic bone diseases, and acute or chronic joint injuries. Pain and disabilities are the major consequences of KOA, with 25% of patients suffering from severe arthralgia. KOA is believed to be a result of the failure of chondrocytes to maintain homeostasis between the synthesis and degradation of the extracellular matrix and from subchondral bone developing osteoarthrosis (4, 5).

Although traditional treatment modalities, including analgesics, physical therapy, and intra-articular steroid (IAS) injections, have long been employed to manage symptoms, the growing need for more effective and minimally invasive interventions has prompted the exploration of novel approaches (6).

Among these newer treatments, motor sparing techniques, genicular nerve radiofrequency ablation has emerged as a viable alternative to conservative therapy and total knee arthroplasty (7).

Genicular nerve ablation is a known procedure to help these cases as they transfer the pain signal of the knee. It is usually reserved for patients with symptomatic knee osteoarthritis who have had failure of conservative treatment and have had failure of or are poor candidates for surgery (8).

However, there is a high failure rate among the patients undergoing the procedure as regarding the efficacy or the duration of pain relief and various methods have been used to increase the rate of success and the duration of the pain relief such as using alcohol in the ablation, cooled radiofrequency or increase the lesions on the nerves (9, 10).

There has recently been considerable interest in the role of radiofrequency ablation (RFA) of the genicular nerves for KOA. In the majority of previous studies, ablation was done via a radiofrequency technique using either fluoroscopy or ultrasound for only three genicular nerves, whereas the knee joint is also supplied by a few other nerves (11, 12). Interestingly, neurolytic agents can also be used to ablate the nerves, and are readily available, less costly, and need less logistic support (13).