Obesity is Tough on Joints

Osteoarthritis is one of several health complications associated with obesity and is one of the leading reasons for hip or knee replacement surgery. Researchers have concluded that obesity is, at the least, an indirect contributor to joint replacement. However, exactly what role extra weight plays in the incidence of joint replacement surgery remains unclear.

In this Canadian study, researchers investigated this potential connection in patients undergoing hip or knee replacement surgery in 2003 and 2004. Patients were assigned to one of four categories (underweight, acceptable weight, overweight, or obese) based on accepted standards for body mass index (BMI). Here's what the researchers found:

Eighty-seven percent of knee replacement patients were considered overweight or obese, as were 72 percent of hip replacement patients.
After adjusting for patient age and gender, obese patients were three times as likely to have knee or hip replacement as compared to people with acceptable weights. Overweight patients were twice as likely to have joint replacement surgery.

“Our data tell us that being obese or overweight not only increases the likelihood of needing a joint replacement, but it also has a negative impact on how well a patient recovers and how long a patient remains in the hospital following surgery,” said an executive with the Canadian Institute for Health Information, which conducted the study. “Being obese or overweight also can increase the necessity for repeat surgeries – modifications to or replacements of the artificial joints – because the extra weight adds more wear and tear on the prostheses.”


Canadian Joint Replacement Registry 2005 Report – Total Hip and Total Knee Replacements in Canada. Ottawa, Ontario, Canada: Canadian Institute for Health Information.