Efficacy of ultrasound therapy for the management of knee osteoarthritis: a systematic review with meta-analysis

SummaryObjectiveTo assess the efficacy of ultrasound therapy (US) for decreasing pain and improving physical function, patient-perception of disease severity, and cartilage repair in people with knee osteoarthritis (OA).MethodsWe conducted a systematic review (to February 2009) without language limits in MEDLINE, EMBASE, Cochrane Library, LILACS, MEDCARIB, CINAHL, PEDro, SPORT-discus, REHABDATA, and World Health Organization Clinical Trial Registry. We included randomized controlled trials of people with knee OA comparing the outcomes of interest for those receiving US with those receiving no US. Two reviewers independently selected studies, extracted relevant data and assessed quality. Pooled analyses were conducted using inverse-variance random effects models.Main resultsSix small trials (378 patients) were included. US improves pain [Standardized Mean Difference (SMD) (95% confidence interval (CI))=−0.49 (−0.79, −0.18), P=0.002], and tends to improve self-reported physical function [SMD (CI)=−0.54 (−1.19, 0.12), P=0.11] along with walking performance [SMD (CI)=0.81 (−0.09, 1.72), P=0.08]. Results from two trials (128 patients), conducted by the same group, show a positive effect of US on pain [SMD (CI)=−0.77 (−1.15, −0.39), P<0.001], self-reported physical function [SMD (CI)=−1.25 (−1.69, −0.81), P<0.001], and walking performance [SMD (CI)=1.47 (1.06, 1.88), P