Obese patients more likely to have complications after total knee replacement surgery

Obese patients have a greater risk of complications following total knee replacement surgery, including post-surgical infections, according to a new literature review recently published in the Journal of Bone and Joint Surgery (JBJS). Because of complications, obese patients are more likely to require follow-up surgery (revision).

Obesity is reaching epidemic proportions, particularly in the United States, and is a well-documented risk factor for the development of osteoarthritis. Arthritis is initially treated nonsurgically, but total joint replacement often becomes necessary if the disease progresses. Consequently, the rate of joint replacements in obese individuals has increased in the last several decades.

"Orthopaedic operations can technically be more difficult in obese people, and it is important for us to know whether there is a higher complication rate in the obese, and if the long-term outcome is worse," says Gino M.M.J. Kerkhoffs, MD, PhD, an orthopaedic surgeon at the Academic Medical Center Amsterdam, University of Amsterdam, and lead author of the study.

Findings include:

• Obese patients have double the rate of infection following total knee replacement surgery compared to non-obese patients.
• Obese patients' rate of infection is higher for both superficial and deep infections.
• The long-term surgical revision rate for obese patients is nearly double that for non-obese patients.

The paper's authors advise that knee replacement surgery not be withheld from obese patients. Rather, obese patients should be well-informed of the likelihood of complications following their total knee replacement, and advised to lose weight before surgery. Orthopaedic surgeons should be prepared to refer them to medical weight-loss professionals, if necessary. The authors also note that weight loss could lessen some patients' osteoarthritis symptoms.

"Although these results are not really surprising," Kerkhoffs says, "for the obese patient, this literature sheds new light on treatment options for symptomatic knee osteoarthritis: a total knee replacement is not the 'easy solution.'"