Therapeutic ultrasound (US) is a widely used intervention in physical therapy to manage pain and to aid in the healing of soft tissue.
This systematic review aimed to determine the effects of therapeutic US on knee osteoarthritis (KOA) symptoms.
PubMed, MEDLINE, EMBASE, Google Scholar, and the Cochrane databases were searched from inception to April 2019. Randomized controlled trials (RCTs) involving adults with symptomatic KOA that compared therapeutic US with a sham or other control were included. The methodological quality of the trials was assessed at the study level using the Cochrane Risk of Bias tool. The quality of evidence at the outcome level- and overall- was assessed using GRADE methodology. Meta-analyses were conducted using random effects models, and heterogeneity was assessed using the I
Four studies (N = 234 participants) were eligible for inclusion in our primary analyses assessing therapeutic US versus sham. The methodological quality of the included RCTs ranged from moderate to very low. Treatment with therapeutic US resulted in small, statistically significant benefits for pain (approximate 9.6% improvement on a 0-100 visual analog scale [95% confidence interval: 2, 17.4%]) and self-reported measures of function (approximate 12.8% improvement on a 0-100 visual analog scale [0.4, 25.2%]). The overall quality of the evidence was very low. No adverse events were reported in any of the included studies.
The use of therapeutic US may provide additional benefits to physical therapy regimens in terms of symptom relief in individuals with KOA. However, it is not possible to make any meaningful recommendations for clinical practice due to the small number of applicable RCTs and the low methodological quality of the RCTs deemed eligible for this study.