No additional benefit of shortwave diathermy over exercise program for knee osteoarthritis in peri-/post-menopausal women: an equivalence trial

SummaryObjectiveTo evaluate the benefit of shortwave diathermy (SWD) supplemented to an exercise program for knee osteoarthritis (OA) in peri-/post-menopausal women.MethodsA double-blind randomized placebo-controlled equivalence trial was conducted in a university hospital. Participants including 113 women aged 50–85 years with primary knee OA were instructed to do regular quadriceps exercise, and randomized to control (n=60) and treatment (n=53) groups receiving sham SWD and therapeutic SWD, respectively. The treatment being evaluated was continuous SWD, 20min/session, 3sessions/week for 3 weeks. The outcomes including Thai Western Ontario and McMaster Universities OA (WOMAC) index, 100-m walking speed, stair ascent-and-descent time, global assessment, patient's satisfaction, and adverse events were assessed at baseline and end of treatment.ResultsAt the end of treatment, both groups had trivial but statistical improvement in all outcomes. Intention-to-treat analysis showed no statistically significant difference between the two groups in all outcomes. Per protocol analysis demonstrated the equivalence in Thai WOMAC total score, as the 95% confidence interval of difference (−0.62, 0.92) was within confidence limits of ±1cm.ConclusionThe addition of SWD to an exercise program for knee OA in peri-/post-menopausal women is not superior to the exercise program alone