The Efficacy of Cryoneurolysis on Chronic Pain in Patients with Knee Osteoarthritis; A Double-blinded Randomized Controlled Sham Trial

Background: The objective was to investigate if cryoneurolysis were superior to sham in reducing pain intensity in patients with chronic knee osteoarthritis. We hypothesized that cryoneurolysis was an effective and safe therapy to reduce chronic pain in patients with knee osteoarthritis. Methods: The study was a randomized, double-blind, sham-controlled. Eighty-seven patients with chronic knee osteoarthritis were randomized to either cryoneurolysis or a sham procedure, followed by an exercise program. The target nerves, anterior femoral cutaneous nerve and infrapatellar branch of the saphenous nerve were identified using transcutaneous electrical nerve stimulation and cryoneurolysis was performed ultrasound-guided. The primary outcome was the difference in average pain at 14d post intervention between the cryoneurolysis and sham group. Results: For the intention to treat analysis, no difference was observed for the primary outcome (0.49, 95% CI [-0.3 ; 1.2], p=0.198). Both groups showed a significant reduction in pain scores 14d post intervention (Cryoneurolysis: -1.9, 95% CI [-2.4 ; -1.3], Sham: -1.4, 95% CI [-1.9 ; -0.8]). At 6 months follow-up, a significant reduction in pain was observed in the cryoneurolysis group compared to sham group (1.1, 95% CI [0.3 ; 1.9], p=0.009). Cryoneurolysis was well-tolerated, with minor, transient adverse effects. Conclusions: This study did not show a clinically relevant reduction in pain after intervention comparing cryoneurolysis and sham. Further studies are needed.