Effectiveness of Thermotherapy Using a Heat and Steam Generating Sheet for Cartilage in Knee Osteoarthritis

[Purpose] Superficial heat treatment is one of the most widely used physical therapies for osteoarthritis (OA). We clinically evaluated the effects of local heat treatment and exercise therapy for knee OA, and evaluated the articular cartilage using magnetic resonance imaging (MRI) T2 mapping. [Subjects and Methods] Eighteen females aged 50–69 (59.5 ± 8.5 years, mean ± SD) years diagnosed with early-stage knee OA were randomly assigned using computer-generated random numbers to either a local heat treatment group (LH group, 9 subjects) or an exercise therapy group (EX group, 9 subjects). These groups were subjected to a 12-week intervention experiment. MRI T2 mapping was performed for cartilage imaging and quantitative evaluation. For clinical evaluation, the Japanese Knee Osteoarthritis Measure (JKOM) and the Timed Up and Go (TUG) test were performed. Both clinical and MRI evaluations were performed at the beginning and end of the intervention (0 week (Time 0) and 12 weeks). [Results] The total JKOM score had a significantly decreased in the LH group at 12 weeks. However, in the EX group the total JKOM scores at Time 0 and 12 weeks were not significantly different. The TUG time in the EX group was significant shorter at 12 weeks, whereas it showed no significant change in the LH group at 12 weeks, though the TUG times of 7 of the 9 patients decreased, exhibiting some improvement. The T2 value of the LH group was significantly shorter at 12 weeks. However, the T2 value in the EX group showed no significant change at 12 weeks. [Conclusion] After local heat treatment using heat- and steam moisture-generating sheets for 12 weeks, we observed improvements in clinical symptoms and walking abilities. Moreover, positive effects on cartilage metabolism were suggested.