Pulsed low-intensity ultrasonography may not reduce symptoms or cartilage loss in knee osteoarthritis

USA: In a new study, it was found that the use of pulsed low-intensity ultrasonography (PLIUS) showed no clinical improvement or reduction in tibiofemoral cartilage thickness loss in knee osteoarthritis (OA). The findings of this study were published in the JAMA Network Open. 

There are no licensed therapies to halt the progression of osteoarthritis in the United States, but animal studies show that pulsed low-intensity ultrasonography (PLIUS) may encourage cartilage regeneration. Allen D. Sawitzke and colleagues conducted this research to investigate the efficacy of PLIUS in providing symptom relief and reduced loss of tibiofemoral cartilage thickness in individuals with knee OA.

From May 22, 2015, through January 31, 2019, a phase 2A, parallel, sham-controlled, double-blind randomized clinical study was undertaken at two Veterans Affairs hospitals in Salt Lake City, Utah, and San Diego, California. Data was evaluated between June 27, 2020, and October 20, 2020. Participants (N = 132) recruited through the US Department of Veterans Affairs with clinical and radiographic indications of early knee OA were randomly allocated to either PLIUS or a dummy device, which was self-administered for 20 minutes daily across the medial compartment of the knee. A 4-week pre-randomization sham run-in phase was followed by a 48-week treatment term for all registrants. Participants were randomly assigned to either PLIUS or sham ultrasonography for 48 weeks. The trial included two co-primary outcomes: clinical improvement as measured by Outcome Measures in Rheumatology cartilage preservation and Clinical Trials as measured by magnetic resonance imaging change in central medial femoral condyle cartilage thickness.

The results of this study stated as follow:

1. The average participant age was 63.6 years, with 119 men (90.2% ).

2. The average (standard deviation) OA symptoms duration was 13.4 years.

3. 70.4% of participants in the PLIUS group experienced symptomatic improvement, compared to 67.3% of participants in the sham group; no statistically significant difference was found in response rates between the treatment groups, and the between-group rate difference of 3.1% did not meet the predefined 10% threshold for clinically significant symptomatic improvement from PLIUS application.

4. Central medial femoral condyle cartilage thickness is reduced by a mean of 73.8 m in the PLIUS group and by 42.2 m in the sham group after 48 weeks of therapy.

5. The 48-week mean difference between the two groups was not statistically significant, and the between-group 48-week difference of –31.7 m did not satisfy the set threshold.

6. During the experiment, there were 99 non-serious adverse events in the PLIUS group and 89 in the sham group. There were no significant adverse events associated with the trial device.

In conclusion, this data may help future trial designers by better specifying expected value ranges and rates of change. In this 48-week experiment, no evidence was found to show that PLIUS, when used as recommended, is beneficial for either cartilage loss in knee OA or its symptoms.

Reference:

Sawitzke AD, Jackson CG, Carlson K, et al. Effect of Pulsed Low-Intensity Ultrasonography on Symptom Relief and Tibiofemoral Articular Cartilage Thickness Among Veterans Affairs Enrollees With Knee Osteoarthritis: A Randomized Clinical Trial. JAMA Netw Open. 2022;5(3):e220632. doi:10.1001/jamanetworkopen.2022.0632

Keywords: femur, osteoarthritis, pulsed low-intensity ultrasonography, articular cartilage, JAMA, rheumatoid arthritis, MRI, cartilage regeneration, cartilage loss, knee osteoarthritis