Efficacy and Safety of Cryoablation Compared with Cooled Radiofrequency Ablation of Genicular Nerves in Advanced Osteoarthritis of the Knee: A Study Protocol of Single-Centric, Assessor-Blinded, Randomized, Parallel-Group, Non-inferiority Study.

Abstract

In patients with symptomatic osteoarthritis knee (OAK), cryoneurolysis (CRYO) and cooled radiofrequency ablation (C-RFA) are reported to be effective and safe; however, they have not been compared directly. The objective of this study is to compare CRYO and C-RFA of the genicular nerve (GN) in terms of efficacy and safety profile in patients with Kellgren and Lawrence (KL) grade ≥ 3 OAK. This single-centric, assessor-blinded, randomized, parallel-group, non-inferiority study will include 80 patients with KL grade ≥ 3 OAK. The patients with ≥ 50% pain relief on diagnostic block of three GNs will be randomized to one of the two groups, i.e., CRYO (n = 40) or C-RFA (n = 40). The three target GNs for the interventions will include: superior medial, superior lateral, and inferior medial. The primary outcome will be efficacy of CRYO or C-RFA at 2, 12, and 24 weeks post-procedure based on the 11-point Numerical Pain Rating Scale. The secondary outcomes will be functional improvement based on 12-item Oxford Knee Score and safety of both the procedures. The study is registered in the Clinical Trials Registry-India. CRYO and C-RFA provide pain relief and improve functional outcome by preventing transmission of pain signals, though by distinct mechanisms. While C-RFA is an established treatment modality, recent evidence supports CRYO in patients with OAK. This study intends to demonstrate non-inferiority of CRYO against C-RFA, thereby supporting the use of CRYO as an additional treatment modality in patients with KL grade ≥ 3 OAK.