Bodyweight and Total Joint Replacements

A discussion about being overweight is one that your orthopaedic surgeon may need to have with you especially if you are considering having your hip or knee replaced.  While this can be a very sensitive and personal issue for some, it is one that needs to be addressed to give you the best chance to have a successful outcome.

Studies have shown that the prevalence of obesity tends increases with age and peaks somewhere between the 60’s and 70’s (Flegal et al 2012). This happens to be the same general age range where patients undergo total joint replacement surgery.

A paper (Westrich et al 2014) that was presented at the recent meeting of the American Academy of Orthopaedic Surgeons (AAOS), concluded that weight loss is associated with better clinical outcomes following a total hip or knee replacement.   This was based on a study of over 6800 patients who underwent a total joint replacement and were followed for 2 years. Those who had a 5% or more decrease in their body mass index (BMI) following surgery had better physical and activity scores than those who maintained or gained weight following surgery.

Previously published studies have shown that obesity is associated with increased complication rates. Medical complications and decreased survival rate of the implant are the most common issues cited for obese and morbidly obese patients who have undergone total hip or knee replacements. Logically, this makes sense as the more stress that is placed on the implant can lead it to fail sooner than expected.

From my standpoint as a joint replacement surgeon, surgery can be much more challenging in someone who is obese. In many cases, it requires me to make a larger incision to obtain the proper exposure and it can take longer to perform the operation.  Longer surgeries lead to more time under anesthesia that can present additional problems for some. Physical inactivity associated with excessive bodyweight or obesity can also present problems with post-operative recovery and rehabilitation.

Weight management is one vital component to having a successful long term outcome from hip or knee replacement surgery.  This is something that needs to be brought up and discussed early in the treatment process.