Using pulsed magnetic field therapy for the treatment of knee osteoarthritis

A double-blind, placebo-controlled trial

P. Nikolakis, J. Kollmitzer, R. Crevenna, C. Bittner, C. B. Erdogmus, J. Nicolakis, University of Vienna, Austria

Pulsed magnetic field therapy is frequently used to treat the symptoms of osteoarthritis in the knee. We conducted a randomized, double-blind comparison of pulsed magnetic field therapy and placebo therapy in patients with symptomatic knee osteoarthritis. Patients received 84 sessions, 30 minutes each, of either pulsed magnetic field therapy or placebo treatment. Patients administered the treatment on their own at home, twice a day for six weeks. 36 consecutive patients were enrolled. 34 patients completed the study, two of whom had to be excluded from the statistical analysis as they had not applied the PMF as instructed. Thus, 15 verum and 17 placebo-treated patients were enrolled in the statistical analysis. After six weeks of treatment, the WOMAC Osteoarthritis Index was reduced in the verum group from 84.1 (+/- 45.1) to 49.7 (+/- 31.6), and from 73.7 (+/- 43.3) to 66.9 (+/- 52.9) in the placebo group (p = 0.03). The following secondary parameters improved in the pulsed magnetic field group more than they did in the placebo group: gait speed during fast walking [+6.0 meters per minute (1.6 to 10.4) vs. -3.2 (-8.5 to 2.2)], stride length during fast walking [+6.9 cm (0.2 to 13.7) vs. -2.9 (-8.8 to 2.9)], and acceleration time in isokinetic dynamometry strength tests [-7.0% (-15.2 to 1.3) vs. 10.1% (-0.3 to 20.6)].

Conclusion: In patients with symptomatic osteoarthritis = Knee arthrosis and magnetic therapy of the knee, PMF therapy can reduce impairment of activities in daily life and improve the knee function.