Effects of short-wave therapy in patients with knee osteoarthritis: a systematic review and meta-analysis

Objective: To evaluate the efficacy and safety of short-wave therapy with sham or no intervention for the management of patients with knee osteoarthritis. Methods: We searched the following databases from their inception up to 26 October 2016: MEDLINE, CENTRAL, EMBASE, Physiotherapy Evidence Database, CINAHL and OpenGrey. Studies included randomized controlled trials compared with a sham or no intervention in patients with knee osteoarthritis. The results were calculated via standardized mean difference (SMD) and risk ratio for continuous variables outcomes as well as dichotomous variables, respectively. Heterogeneity was explored by the I 2 test and inverse-variance random effects analysis was applied to all studies. Results: Eight trials (542 patients) met the inclusion criteria. The effect of short-wave therapy on pain was found positive (SMD, −0.53; 95% CI, −0.84 to −0.21). The pain subgroup showed that patients received pulse modality achieved clinical improvement (SMD, –0.83; 95% CI, –1.14 to −0.52) and the pain scale in female patients decreased (SMD, −0.53; 95% CI, −0.98 to −0.08). In terms of extensor strength, short-wave therapy was superior to the control group ( p < 0.05, I 2 = 0%). There was no significant difference in the physical function (SMD, −0.16; 95% CI, −0.36 to 0.05). For adverse effects, there was no significant difference between the treatment and control group. Conclusion: Short-wave therapy is beneficial for relieving pain caused by knee osteoarthritis (the pulse modality seems superior to the continuous modality), and knee extensor muscle combining with isokinetic strength. Function is not improved.