Effects of low-intensity pulsed ultrasound on knee osteoarthritis: A systematic review and meta-analysis of randomized controlled trials

Chen H, Wang Z, Zhang X, Sun M · Clinical Rehabilitation

Pain fell by a mean difference of 0.95 points on the visual analogue scale (95% CI -1.43 to -0.48, 12 trials, I2 86.6%) and the WOMAC by 4.35 points (95% CI -8.30 to -0.40, 6 trials, I2 56.5%); the Lysholm score, Lequesne index, range of motion and 50-metre walking time also moved. Given alone rather than added to something else, the pain effect was larger (MD -1.96, 95% CI -2.79 to -1.14). The trials fed no cartilage measurement into the pooling: individual trials recorded Noyes cartilage defects, MRI T2 mapping and femoral articular cartilage thickness, and the review synthesises only symptoms and function.

Population

Patients with knee osteoarthritis in 13 randomised trials, searched in English and Chinese to March 2022

Intervention

Low-intensity pulsed ultrasound, alone or added to drugs or other physical therapy

Comparator

Sham, no treatment, drugs alone or the other therapy alone, depending on the trial

Limitations

Heterogeneity was high on the primary pain outcome (I2 86.6%) and dropping a single trial only moved it to 77.3%. Language limited to English and Chinese. The structural endpoints that some included trials measured are listed in the outcomes table and never pooled or reported, so this review says nothing about cartilage despite its trials having looked. LIPUS itself has been cleared in the United States for fresh fracture and nonunion for over twenty years, which is where the mechanism claim comes from rather than from a joint. Funded by the Department of Education of Liaoning Province (LJKZ1048); the authors declare no conflicts of interest.