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21-03-2022 | Rheumatology | News | Article

Pulsed low-intensity ultrasonography shows no benefit in knee OA

Author: Laura Cowen

medwireNews: A 48-week course of pulsed low-intensity ultrasonography (PLIUS) does not reduce symptoms or slow cartilage loss in patients with idiopathic knee osteoarthritis (OA) relative to sham treatment, US study findings indicate.

Writing in JAMA Network Open, Allen Sawitzke (University of Utah, Salt Lake City) and co-authors explain that although OA is a major cause of disability in the USA there are currently “no approved treatments to slow progression.”

However, studies in animal models have suggested that PLIUS – which is already used in fracture healing – may promote cartilage growth, they add.

The researchers therefore investigated the utility of PLIUS in a phase 2A trial including 132 adults (mean age 63.6 years, 90% men) with symptomatic and radiographic idiopathic knee OA (mean duration 13.4 years) at two Veterans Affairs hospitals.

After a 4-week sham treatment run-in period, participants were randomly assigned to receive a PLIUS or a sham ultrasonography device, which they self-administered to the medial compartment of the knee for 20 minutes per day for 48 weeks.

Using OMERACT-OARSI criteria, the researchers observed that 70.4% of participants in the PLIUS group experienced symptomatic improvement at 48 weeks compared with 67.3% of those in the sham group, a nonsignificant difference.

Furthermore, the 3.1% difference between the two groups did not meet the predefined 10% threshold for clinical significance.

There was also no significant difference between the two groups with respect to change in central medial femoral condyle cartilage thickness after 48 weeks, with mean reductions of 73.8 μm and 42.2 µm in the PLIUS and sham groups, respectively, and a mean difference of 31.7 µm, which did not meet the criteria for clinical benefit (≥33 µm).

Furthermore, measurements of serum and urine biomarkers of OA suggested “no biochemical signal of therapeutic response,” say the researchers.

Sawitzke et al conclude: “Although PLIUS benefit was not observed and promising signals for future investigation were not immediately apparent, this clinical trial provides subjective, objective (joint space width by radiographic and cartilage thickening by MRI), and biomarker information.”

They add: “This information may aid future trial design by better defining expected ranges of values and rates of change.”

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2022 Springer Healthcare Ltd, part of the Springer Nature Group

JAMA Netw Open 2022; 5: e220632