Obesity can lead to a wide range of health problems in adults, one of which is osteoarthritis. Osteoarthritis is one of the leading reasons for people to have hip- or knee-replacement surgery.

It doesn't take much, then, to assume that obesity contributes to having to have a joint replaced. Researchers in this study attempted to determine exactly what role obesity plays in joint replacement, and whether obese patients are more likely to need their hip joints or knee joints replaced.

In this study, the authors looked at the health records of more than 17,000 people undergoing hip or knee replacement surgery. The patients were then grouped into one of four categories - obese, overweight, acceptable weight, or underweight - based on their body mass index, or BMI.

Results: Eighty-one percent of joint replacement patients with BMI measurements were classified as obese or overweight. Only 18 percent had an "acceptable" weight, with a BMI between 18.5 and 24.9. After adjusting for age and gender, obese patients were three times as likely to have a joint replaced compared to acceptable weight patients; overweight patients were twice as likely to have joint replacement surgery.

The authors concluded that being overweight or obese "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 hospital following surgery." They added that being obese or overweight could cause other complications, such as repeat surgeries, because the extra weight could lead to more wear and tear on an artificial joint.

For more information, visit www.chiroweb.com/find/archives/musculoskeletal/extremities.

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