Extracorporeal Magnetotransduction Therapy (EMTT) for Midfoot Osteoarthritis: A Prospective Pilot Study of Pain and Functional Outcomes

Extracorporeal magnetotransduction therapy (EMTT) is a high-energy electromagnetic modality that delivers field strengths of 80–150 mT, effective transduction power > 60 kT/s, and dual-frequency architecture with pulse repetition near 8 Hz and oscillations of 100–300 kHz. This prospective pilot study evaluated pain and functional outcomes in patients with symptomatic midfoot osteoarthritis (OA). Eight patients (13 feet; five bilateral and three unilateral cases) with radiographic Kellgren–Lawrence (KL) grade 3 or 4 midfoot OA received eight EMTT sessions over four weeks. Outcomes were measured at baseline, after the eighth treatment at four weeks, and at 3-month and 6-month follow-up using the 0–10 Visual Analog Scale (VAS) and Foot and Ankle Ability Measure—Activities of Daily Living (FAAM-ADL). VAS demonstrated a significant overall effect of time (F(3,36) = 3.93, p = 0.016), with mean scores decreasing from 4.15 ± 1.63 at baseline to 2.62 ± 1.98 at 3 months and 3.00 ± 2.08 at 6 months. Bonferroni-adjusted baseline-to-follow-up contrasts approached significance at 3 months (p = 0.067) and were not significant at 6 months (p = 0.150). FAAM-ADL improved significantly over time (F(3,30) = 13.76, p < 0.001), increasing from 61.7% ± 9.9% at baseline to 81.8% ± 11.1% at 6 months. No treatment-related adverse events were observed; one participant proceeded to surgery by 6 months and was classified as a treatment failure. These preliminary findings suggest that EMTT is safe and may provide clinically meaningful functional improvement in selected patients with midfoot OA; larger sham-controlled trials are needed.