RESUMO
Instrumental physiotherapeutic treatment using portable devices is optimal for patients with rheumatic diseases due to the devices' greater accessibility. However, there are still issues concerning the efficacy of physical factors generated by portable equipment in osteoarthritis (OA), mostly due to the limited evidence. OBJECTIVE: To study the efficacy and safety of long-term use of the portable magnet therapy device ALMAG+ (Almag Active) in knee OA (KOA). MATERIALS AND METHODS: A double-blind, randomized, placebo-controlled, prospective, 55-week clinical trial of the medical device was conducted. The study included patients with primary and secondary (associated with immunoinflammatory rheumatic diseases) KOA stages I-III according to Kellgren-Lawrence diagnosed using generally accepted criteria (R. Altman et al., 1986). Enrollment of patients with secondary KOA was allowed given that the remission or low disease activity was achieved. During the study patients had to receive steady drug therapy. No intra-articular injections of glucocorticosteroids, hyaluronic acid, PRP, and physiotherapy procedures for knees (electrotherapy, shockwave therapy, heat therapy, hydrotherapy, peloid therapy) were allowed three months or less before the enrollment and throughout the study. According to the approved protocol, 77 patients (mean age 52.73±12.97 years) from two research centers participated in the study: 32 (41.6%) were males, and 45 (58.4%) were females. Primary KOA occurred in 41 (52%) patients, 36 (46.8%) patients had secondary KOA (associated with rheumatoid arthritis, ankylosing spondylitis, Sjögren's disease, psoriatic arthritis, systemic lupus erythematosus, or diffuse scleroderma). All patients received NSAIDs as a concomitant therapy, 24.7% received diacerein, 28.6% received disease-modifying anti-rheumatic drugs, 2.6% received methylprednisolone up to 8 mg/day, and 9% received biologic therapy. After randomization, 40 (52%) patients received placebo treatments (Group 1) and 37 (48%) received active treatments (Group 2). Both groups were comparable in the main parameters. The proportion of smokers was higher in Group 2, but the difference was not statistically significant. During the 55-week follow-up, three courses of 18 daily home magnet therapy procedures each were performed. RESULTS: In both groups, starting from week 5 of the study, an improvement of pain on movement and at rest according to VAS compared to the baseline (p<0.01 at all assessment time points) was observed, which can be explained by a pronounced placebo effect, often observed in OA. The improvement of pain at rest was more prominent in Group 2 vs. Group 1 at Week 21 (p=0.038) and Week 55 (p=0.017) of the study, probably due to the anti-inflammatory effect. The overall WOMAC index score was also lower in Group 2 vs. Group 1 at Weeks 21 and 55 (p=0.03 at both time points). The mean articular cartilage thickness, determined by ultrasound, reduced in Group 1 and remained practically unchanged in Group 2 (p=0.011). No adverse events associated with the use of the ALMAG+ (Almag Active) device, according to the attending physician, and no exacerbations of immunoinflammatory rheumatic diseases during the study period were reported. CONCLUSION: The results of a double-blind, placebo-controlled study of magnet therapy using a portable device demonstrated analgesic, anti-inflammatory, and structure-modifying effects of this type of physiotherapeutic treatment. No adverse events and exacerbations of rheumatic diseases associated with the study treatment have been reported.