Effect of radiofrequency ablation of genicular nerves on the isokinetic muscle strength of knee joint in patients with osteoarthritis knee: a randomized double-blind sham controlled clinical trial

Background This randomized controlled trial evaluated the effect of radiofrequency ablation (RFA) of genicular nerve on muscle strength in osteoarthritis (OA) knee patients with chronic pain. Methodology Fifty-four patients with chronic knee OA, experiencing significant pain (visual numeric rating scale [VNRS] >50) and moderate to severe disease (Kellgren Lewis grade >= 2) were enrolled. Group 1 received RFA of genicular nerves of the affected knee while Group 2 received a sham procedure. The primary outcome was change in knee muscle strength evaluated using isokinetic peak torque (IPT) using IsoforceTM isokinetic dynamometer at 3 months. Secondary outcomes included changes in pain scores, function, perceived effect of the treatment and compliance to physiotherapy. Results At 3 months, significant difference was observed between IPT of flexor muscle at 60 degrees and 180 degrees between the treatment and the Sham control (P-value = .01). No significant difference was observed in the extensor muscle strength. Within-group analysis revealed a significant increase in the IPT values for both extension and flexion at 60 degrees/sec and 180 degrees/sec evident across various time intervals. Group1 consistently reported lower VNRS scores at all time points. Western Ontario and McMaster Universities Osteoarthritis Index scores of both groups were significantly different at all timepoints, with higher scores indicating reduced functionality in Group2. The Global Perceived Effect and compliance to physiotherapy were higher in Group1 patients at all times of follow up albeit decreasing trend in later periods. Conclusion Application of RFA to genicular nerves in chronic OA knee patients resulted in better pain relief, improved functionality, and increased muscle strength at extension and flexion at 3 months follow-up. Clinical Trial Registry of India - CTRI registration number CTRI/2020/05/025363.