Treatment using 448 kHz capacitive resistive monopolar radiofrequency improves pain and function in patients with osteoarthritis of the knee joint: A randomised controlled trial

Objective: This study investigated whether capacitive resistive monopolar radiofrequency (CRMRF)-based treatment improves pain and function among patients with osteoarthritis of the knee. Design and setting: Three-group randomised controlled trial with concealed allocation, participant blinding and intention-to-treat analysis. Forty-five patients diagnosed with osteoarthritis, from the waiting list for physiotherapy at a local hospital were enrolled. Intervention: Participants in the active and sham groups received eight sessions of CRMRF and sham-CRMRF respectively over four weeks, along with standard care. The control group received standard care only. Assessment: Pain and function were measured at four time points: week zero (baseline), week four (post intervention), week eight and week 16 (two follow-ups) using visual analogue scale (VAS), Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, timed up and go (TUG) test and knee range of motion (ROM). Results: For pain (VAS), there were clinically significant changes in the active group at post treatment compared to sham (Mean difference: 0.79 (95% CI: 0.29 to 1.3), effect size: 1.3) and control (Mean difference: 0.82 (95% CI: 0.32 to 1.3), effect size: 1.5), and at one-month follow-up compared to control (Mean difference: 0.68 (95% CI: 0.10 to 1.3), effect size: 1.1). For function (WOMAC), there was clinically significant change in the active group at post treatment compared to control (Mean difference: 1.3 (95% CI: 0.02 to 2.6), effect size: 0.94), but not compared to sham. No meaningful differences were noted for TUG or knee ROM. No differences were noted at three-month follow-up for any outcomes. Conclusion: CRMRF treatment can improve pain and function in patients with knee osteoarthritis in the short term. Trial registration: NIHR-CRN study ID: 20264.