Effects of therapeutic ultrasound in patients with knee osteoarthritis: A systematic review and meta-analysis

 

Background

Therapeutic  ultrasound (US) is a treatment for knee osteoarthritis (KOA), but its  efficacy and safety are unclear. The objective of this study is to  quantify the effect of US on pain relief and function recovery in KOA,  and to analyze the US treatment duration and parameters on treatment  outcome.

Methods

We searched PubMed, MEDLINE, EMBASE, Google Scholar, Cochrane databases and ClinicalTrials.gov  databases up to 7 April 2023. RCTs that compared the efficacy of  therapeutic US with the control in KOA were included in the study, and  the methodological quality of the trials was assessed using the Cochrane  Risk of Bias tool.

Results

Twenty-one  RCTs (1315 patients) were included. US had a positive effect on visual  analog scale (VAS) (SMD = -0.64, 95% CI [-0.88, -0.40], I2 = 71%) and Western Ontario and McMaster Universities (WOMAC) total scale (SMD = -0.45, 95% CI [-0.69, -0.20]; I2 = 67%) . Pulsed US with an intensity ≤2.5 W/cm2 reduced visual analog scale (VAS), and differed in sessions (24 sessions (SMD = -0.80, 95% CI [-1.07, -0.53], I2 = 0%) vs 10 sessions (SMD = -0.71, 95% CI [-1.09, -0.33], I2= 68%)). For pulsed US, a duration of treatment of 4-8 weeks (SMD = -0.69, 95% CI [-1.13, -0.25], I2 = 73%) appeared to be superior to ≤4 weeks (SMD = -0.77, 95% CI [-1.04, -0.49], I2 = 0%) for reducing visual analog scale (VAS). No US treatment-related adverse events were reported.

Conclusion

Therapeutic  US may be a safe and effective treatment for patients with KOA. The  mode, intensity, frequency, and duration of US may affect the  effectiveness of pain relief. Pulsed US with an intensity ≤ 2.5 W/cm2, 24 sessions, and a treatment duration of ≤ 4 weeks appears to have better pain relief.