The aim of this study was to explore the effects of therapeutic ultrasound with sham or no intervention on pain, physical function and safety outcomes in patients with knee osteoarthritis. This systematic review was searched on CENTRAL, EMBASE, MEDLINE, CINAHL, Physiotherapy Evidence Database, Open Gray on 4 September 2015. Trials included randomized controlled trials that compared therapeutic ultrasound with a sham or no intervention in patients with osteoarthritis of the knee. Eligible trials and extracted data were identified by two independent investigators. Standardized mean differences (SMDs) and 95% confidence interval (CI) were calculated for pain and physical function outcomes. Heterogeneity was assessed by the I2 test and inverse-variance random-effects analysis was applied to all trials. Ten randomized controlled trials (645 patients) met the inclusion criteria. Therapeutic ultrasound showed a positive effect on pain (SMD = -0.93, 95%, CI = -1.22 to -0.64, p < 0.01, p for heterogeneity = 0.12, I2 = 42%). For physical function, therapeutic ultrasound was advantageous for reducingWestern Ontario and McMaster Universities physical function score (SMD = -0.37, 95% CI = -0.73 to -0.01, p = 0.04, p for heterogeneity = 0.94, I2 = 0%). In terms of safety, no occurrence of adverse events caused by therapeutic ultrasound was reported in any trial.
The authors suggested that therapeutic ultrasound is beneficial for reducing knee pain and improving physical functions in patients with knee osteoarthritis and could be a safe treatment.