Associations of knee muscle force, bone malalignment, and knee-joint laxity with osteoarthritis in elderly people.

The study did not measure diagnosed osteoarthritis as an outcome; it compared muscle force in knees classified as having possible malalignment or possible laxity. Participants were healthy older adults with no disease or pain that would make participation difficult, so the findings may not apply to people with symptomatic knee osteoarthritis. Malalignment was assessed by a modified standing angle at a community centre, not by X-ray or MRI, and the authors state it is unclear whether this correctly identifies knee deformation or its association with osteoarthritis. Only the right leg was measured, and group sizes were uneven, with only 15 knees in the group classified as having both possible malalignment and possible laxity. No intervention was tested, so the study cannot show that strengthening knee flexors prevents osteoarthritis or improves function.

The authors state there was no conflict of interest related to this study.

Do not conclude that knee flexor weakness causes osteoarthritis or that strengthening knee flexors prevents it. This study measured associations in healthy older adults, did not test an intervention, and did not report diagnosed osteoarthritis outcomes; the malalignment measure was modified and the authors state it may not correctly identify knee deformation.