Knee Replacement While Obese

Obese patients may experience a riskier knee replacement surgery

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) Knee replacement surgery can be an effective way to treat osteoarthritis. But according to one review, it may pose additional risks for obese patients.

From a review of previous studies, researchers found that obese patients may face additional risks during knee replacement surgery. Additionally, their joint replacements may not last as long.

These researchers suggested that obese patients should consider the risks of knee replacement surgery.

"If you are obese, talk to your doctor about losing weight."

Saif Salih and Paul Sutton, of the Department of Trauma and Orthopaedics at Northern General Hospital, conducted this review.

Obesity can put people at risk for several health problems, including heart disease, type 2 diabetes and cancer. Obese people are also at risk for osteoarthritis as their muscles and bones have trouble supporting excess weight.

Osteoarthritis is a condition in which cartilage and joints wear down, leading to pain, stiffness and reduced mobility.

According to the authors of this review, 27 million Americans have osteoarthritis, most commonly in the knees.

Some patients with osteoarthritis in the knee choose to have a knee replaced through surgery.

The authors of this review claimed that knee replacement operations can be more challenging with obese patients.

According to three studies on knee replacements in obese patients, the new knees were more likely to be aligned improperly and there was a higher risk of blood loss. In one study, post-surgical complications occurred in 32 percent of obese participants.

Moreover, knee implants may not last as long in obese patients. One study found that, at seven years post-surgery, obese patients were significantly more likely than non-obese patients to have an implant failure.

The authors also referenced a previous analysis of studies showing that rates of knee implant revision surgery, or surgery in which the replacement has to be fixed or redone, were 1.79 times higher in obese patients compared to patients with normal BMIs.

Morbidly obese patients, or those with a body mass index over 35, had slower recoveries and a greater rate of complications, the authors noted.

Obese patients experienced improvements in osteoarthritis symptoms after knee replacement surgery, according to three studies.

However, according to one prospective study, only 14 percent of obese patients lost weight after the knee replacement, while 21 percent gained weight.

The researchers concluded that obese patients with knee osteoarthritis were at a greater risk of experiencing complications, including joint failure and revision.

These researchers suggested that obese patients should be aware of the increased risks of surgery and the benefits of weight loss before treatment.

This review was published in BMC Sports Science, Medicine & Rehabilitation on December 4.

The authors declared no competing interests. They did not disclose any funding information.

Review Date: 
December 6, 2013
Last Updated:
December 31, 2013