Obesity linked to spike in knee replacements among young adults

While often considered a procedure for older adults or sports enthusiasts, knee replacements are becoming more common in the younger population. A new study finds that rising obesity rates in the U.S. may be a factor in the increasing number of knee replacements in people age 65 and younger.    

The new study, Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement (FORCE-TJR), analyzed 9,000 knee replacement patients from 125 orthopedic surgeons in 22 states. The results showed that patients age 65 and younger were more likely to be obese. In fact, 55 percent of younger patients were obese compared to 43 percent of those older than 65.

According to the study, 11 percent of younger patients were considered severely obese, or a B.M.I. greater than 40, compared to only 5 percent of the older patients. The FORCE-TJR study also found that younger patients experience an equal level of pain and disability before surgery as older patients.

While the numbers are alarming, one Elgin, Illinois-based orthopedic surgeon, Dr. Shawn Palmer, orthopedic surgeon on staff at Advocate Sherman Hospital says he doesn’t see a link between obesity and knee replacements. According to Palmer, while being of a heavier weight does increase contact pressure on the knees, this does not mean a person will develop knee arthritis.

 “Certainly, our population is becoming more obese, but I do not see a direct correlation between increasing body weight and the need for knee replacements,” Dr. Palmer says. “Arthritis, which is the main cause of knee pain and disability, is first and foremost a genetic predisposition. Lifestyle habits such as chosen activities also come into play. However, obesity is not predictive of knee arthritis.”

More than 600,000 knee replacements are performed each year, based on American Academy of Orthopaedic Surgeons data. This number is expected to grow to 3.5 million by 2030.