A Pilot Study Investigating Clinical and Functional Outcomes of Novel Double-Coil rPMS in Knee Osteoarthritis

Background: Knee osteoarthritis (KOA) is one of the leading causes of chronic pain and long-term disability worldwide. Despite its high prevalence, KOA remains underrepresented in repetitive peripheral magnetic stimulation (rPMS) research. While total knee arthroplasty remains the definitive treatment, there is a growing need for non-invasive approaches to reduce symptoms in patients seeking conservative alternatives or awaiting surgery. Methods: Thirty patients with KOA underwent a non-invasive treatment program consisting of eight sessions of double-coil repetitive peripheral magnetic stimulation (rPMS) over three weeks. Outcome measures included pain intensity assessed by the Visual Analog Scale (VAS), functional ability evaluated by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Timed Up and Go test (TUG), and joint mobility measured as knee flexion and extension. Clinical relevance was evaluated using the Minimal Clinically Important Difference (MCID), and subgroup analyses were performed according to Kellgren-Lawrence (KL) grade. Results: Double-coil rPMS was associated with statistically and clinically significant improvements in all outcomes. MCID responder rates exceeded 80% for VAS and TUG, exceeded 70% for WOMAC, and approached 50% for joint mobility outcomes. Subgroup analysis indicated that patients with lower KL grades experienced greater pain reduction, whereas those with higher grades showed greater functional gains. Conclusions: Double-coil rPMS provided preliminary evidence of potential clinical benefit as a non-invasive approach in patients with KOA. Given the single-arm pilot design, the findings should be interpreted cautiously and require confirmation in adequately powered randomized controlled trials with longer follow-up.