Exercise is widely recommended as a first-line treatment for hip osteoarthritis, a condition affecting millions of people worldwide. But a new Cochrane review led by researchers at the University of Sydney and the University of Melbourne suggests the benefits may be more modest than previously thought. 

The review found exercise can improve pain and physical function in people with hip osteoarthritis, however the average improvements were smaller than the threshold researchers typically consider to be meaningful.

Co-lead author Associate Professor Michelle Hall from the Sydney Musculoskeletal Research Centre and the School of Health Sciences at the University of Sydney said the findings highlight the need for more nuanced understanding of what exercise can achieve. 

“Exercise is recommended as a primary treatment for hip osteoarthritis, and this review doesn't overturn that,” she said. 

“But it does suggest we should be honest with patients that the average benefit may be modest, and that we need better-designed trials to understand who benefits most and from which type of exercise.

“We know people are generally worse off when they stop moving altogether. The message isn’t to avoid exercise. It’s that we need better evidence to determine which types of exercise work best for different people with hip osteoarthritis.”

Associate Professor Hall said one of the challenges clinicians face is that much of what is known about osteoarthritis comes from studies of the knee rather than the hip. 

“Hip osteoarthritis has traditionally received less research attention than knee osteoarthritis, so we’ve often assumed treatments would work similarly across both joints,” she said. 

“But we’re learning that’s not always the case. For example, weight loss has clear benefits for knee osteoarthritis, but we haven’t seen the same effects for hip osteoarthritis.

“This is why we need to better understand how exercise works, who it works for, and whether some people are more likely to benefit than others.”

Published in the Cochrane Database of Systematic Reviews, the review analysed 18 clinical trials involving 1368 people with hip osteoarthritis. Participants were mostly women and ranged from 53 to 74 years old. The studies included in the review examined a variety of exercise programs, including strengthening, aerobic and mind-body exercises, with interventions lasting between two and 52 weeks. 

Compared with no treatment or usual care, exercise reduced pain by an average of around seven points on a 100-point scale. The researchers note that experts generally consider a 12-point improvement necessary for patients to notice a meaningful difference in daily life. Similar results were seen for physical function, although the thresholds used have largely been developed from knee osteoarthritis research and may not fully reflect the experiences of people with hip osteoarthritis. 

The review also found little evidence that exercise improved quality of life for people with hip osteoarthritis.