Abstract:
Background: Shortwave diathermy (SWD) has been prescribed for years without definitely scientific proof of its effect. Design and methodology of the previous studies were still questionable. Objective: To compare the effectiveness of SWD for pain relief in knee osteoarthritis. Study design: A double blind randomized placebo-controlled trial. Materials and Methods: One-hundred and thirty-two patients with knee pain were randomized to control group (n=66) receiving sham SWD, or treatment group (n=66) receiving SWD, 15-20 min/session, 3 sessions / week, for 3 consecutive weeks. Outcome measured: WOMAC score (total score, pain, stiffness, and function dimensions), gait speed, global assessment and patient's satisfaction. Results: There was no statistically significant difference between the treatment and control groups in all dimensions of WOMAC score, patient gait speed, global assessment and incidence of adverse events. Subgroup analysis based on baseline WOMAC score also demonstrated the same results. Only the patient's satisfaction score was significantly different (p=0.015); with higher percentage of very satisfied subjects in treatment group. The SWD compliance and amount of NSAID used were also higher in the treatment group. (p = 0.002, 0.021 respectively). But the percentage of subjects with good exercise compliance was higher in the control group. However, the two groups were non-comparable in the following parameters; duration of disease, SWD compliance, exercise compliance and amount of NSAID used. After statistical adjustment using multiple linear regressions analysis, a trivial improvement (approximately 9% difference) of WOMAC score in the treatment group over the control group was revealed. The adverse events of SWD were not serious and not different between 2 groups (approximately 6%). Conclusion: There was no evidence to confirm the effectiveness of SWD for OA knee patients using this treatment protocol. However, other SWD treatment protocolshould be re-evaluated to confirm the effectiveness
