Weight-Loss Drugs May Reduce Knee Replacement Needs
Research indicates that using weight-loss medications for at least three years could significantly decrease the number of knee replacements required each year.
Osteoarthritis impacts over 500 million individuals worldwide, with knee arthritis being the most prevalent form. In the US alone, approximately 14 million people are affected, while the UK sees more than 5 million cases. Many of these individuals will eventually need knee surgery, as evidenced by the 120,000 knee replacements performed annually in the UK.
Carrying excess weight dramatically heightens the risk of developing knee arthritis due to increased pressure on the joints.
Earlier studies have indicated that weight-loss medications alleviate pain associated with knee osteoarthritis. Recent findings suggest that drugs like Mounjaro and Wegovy—or diabetes medications such as Ozempic—might also help in delaying or preventing the necessity for knee surgeries.
Researchers from the University of Maryland School of Medicine analyzed data from 6.8 million adults diagnosed with knee osteoarthritis between 2010 and 2024.
They compared a group of 42,000 patients who had been on GLP-1 medications for at least a year with a similar number of patients who had not used these drugs. Additionally, they focused on nearly 31,000 patients who had taken the medications for three years.
Over an eight-year period post-diagnosis, participants were regularly monitored to evaluate the need for knee replacement surgery.
The study, published in Regional Anesthesia & Pain Medicine, revealed that one year on GLP-1 medications correlated with a 1.4% reduction in the likelihood of needing knee replacement at the three-year mark, rising to a 2.8% decrease after eight years.
The most significant risk reduction was observed with newer weight-loss treatments and longer durations. For example, taking semaglutide or tirzepatide for three years was linked to nearly a 5% lower probability of requiring knee replacement by the eight-year follow-up.
The researchers estimated that if all candidates with knee arthritis and obesity or metabolic disorders used semaglutide or tirzepatide for three years, it could result in approximately 14,400 fewer knee replacements annually in the US and over 1,500 in the UK.
The authors remarked that their findings support the idea that GLP-1 receptor agonists might affect knee osteoarthritis through complementary anti-inflammatory and pain-relieving pathways.
Mark Bowditch, a consultant knee surgeon and former president of the British Orthopaedic Association, commented on the findings, suggesting that GLP-1 receptor agonists may have certain beneficial effects on inflammation and possibly cartilage protection through mechanisms that don’t depend on weight alone. However, he emphasized caution, noting that the study does not definitively prove these drugs can prevent surgery.
“GLP-1 receptor agonists are not approved for treating osteoarthritis, and we strongly advise against using them for this purpose outside clinical research,” he stated.
Professor Lucy Donaldson, research director at Arthritis UK, remarked that the research might deepen understanding of how weight-loss medications could assist some individuals in postponing or avoiding joint-replacement surgeries. She highlighted the importance of maintaining a healthy weight, especially in weight-bearing joints like the knees and hips. “For those who can stay active, even modest weight loss can enhance symptoms and slow the progression of osteoarthritis,” she noted.
