Taking weight-loss drugs for at least three years could prevent thousands of knee replacements annually, according to a new study. Researchers at the University of Maryland School of Medicine analysed data from 6.8 million adults diagnosed with knee osteoarthritis between 2010 and 2024, focusing on those taking GLP-1 medications such as Mounjaro, Wegovy, and Ozempic.
The study, published in Regional Anesthesia & Pain Medicine, found that patients who took these drugs for three years had a nearly 5-percentage-point lower risk of needing knee replacement surgery over an eight-year follow-up period. The authors estimate that if all eligible patients with knee arthritis and obesity took semaglutide or tirzepatide for three years, there could be up to 14,400 fewer knee replacements each year in the US and more than 1,500 fewer in the UK.
Globally, over 500 million people have osteoarthritis, with knee arthritis affecting about 14 million in the US and over 5 million in the UK. Being overweight significantly increases the risk by placing greater load on the joints. Previous studies have shown weight-loss drugs can reduce pain from knee osteoarthritis.
Mark Bowditch, a consultant knee surgeon and immediate past president of the British Orthopaedic Association, cautioned that the findings do not prove these drugs prevent surgery, noting they are not approved for osteoarthritis treatment outside clinical trials. Prof Lucy Donaldson of Arthritis UK said the research could help understand the potential of weight-loss medications to delay or avoid joint replacement, emphasising that maintaining a healthy weight is crucial for managing osteoarthritis.
