Evaluation of the efficiency and safety of magnet therapy for osteoarthritis. Results of the multicenter blind placebo-controlled study COSMO (Clinical Evaluation of Current Magnet Therapy for Osteoarthritis)

Magnet therapy (Mt) is a well-known physiotherapy technique that is widely used to treat knee osteoarthritis (OA). Objective: to determine the efficiency and safety of Mt for knee OA.Subjects and methods. A study group consisted of 231 patients with knee OA (77.9% were women; mean age,61.9+12.2 years; body mass index, 30.6+5.8 kg/m2; median disease duration, 5.0 [2, 0; 10.0] years). The patients were randomly assigned to two groups. Group 1 patients received Mt with an ALMAG+ device for 14 days; Group 2 had false Mt with a completely imitating ALMAG+ device that failed to create a magnetic field. The investigators evaluated the changes of the WOMAC index, pain intensity at rest and during movement on a 100 mm visual analogue scale (VAS), the need for nonsteroidal anti-inflammatory drugs (NSAIDs), and the degree of improvement, as assessed by patients (on a 5-point scale).Results and discussion. During the therapy, there was a statistically significant pain and stiffness reduction and functional improvement. Thus, there were decreases in the median WOMAC pain scores from 231 [180; 290] to 110 [60; 166.3] (p<0.001) in Group 1, from 212.4 [145; 260] to 143 [76.5; 200] (p<0.001) in Group 2, in pain intensity at rest from 47 [27.8; 60] to 20 [10; 30] mm (p<0.001) in Group 1; from 40 [20; 57.5] to 20 [7.5; 40] mm (p<0.001) in Group 2. During the therapy, there was also a reduction in the need for NSAIDs: the drug was discontinued or its dose reduced in 33.1% and 16.8% of the patients in Groups 1 and 2, respectively (p=0.006). The changes of all parameters were statistically more significant in Group 1 than in Group 2. Treatment results were assessed as good and excellent by 58.5% and 39.8% patients in Groups 1 and 2, respectively (p<0.001). No serious adverse events to true and false Mt were observed. Therapy was discontinued due to increase of joint pain in two patients who received false Mt.Conclusion. Short-term Mt provides a significant improvement in patients with knee OA. Mt is well tolerated and causes no serious complications