Featured Co-morbidity: Osteoarthritis
Osteoarthritis in the knee is increasingly common — twice as common as it was in 1950, according to a
study just published in Proceedings of the National Academy of Sciences. Today 20 percent of adults age 45 or older are affected. More sedentary lifestyles are believed to contribute, but there is no denying that obesity plays a large role.
One estimate states that obesity is a risk factor in 69 percent of those who have knee replacement surgery and 27 percent of those who have hip replacement surgery. That is what
John McInnis, MD, an Emerson orthopedic surgeon who specializes in hip and knee replacement, observes in his practice.
“About two-thirds of the patients who come for knee replacements are obese,” he says. “I tell them they should lose weight — any way they can — before having their joint replaced. I acknowledge the pain they are in, and I explain what is going on. For example, when they walk up a flight of stairs, the pressure on their knees is three times their body weight. Over time, the cartilage has broken down. I also worry about overweight or obese individuals who tell me that they exercise aggressively. The knees can’t take it.”
Patients often say they will lose weight after
joint replacement surgery. However, a recent study of patients who claimed they were unable to lose weight because knee pain kept them from exercising and went on to have knee replacement surgery found that fewer than 10 percent lost weight after the joint was replaced. Patient safety is a concern, because obese patients are at risk for complications when they have orthopedic surgery, Dr. McInnis adds.
“We worry about the increased risk of wound problems, infections — including the development of a septic joint, which can be life-threatening — and DVTs (deep vein thrombosis),” says Dr. McInnis.
“Then there is recovery, which for an obese individual is much tougher and often prolonged, sometimes requiring months.” Failure of the prosthesis itself is a possibility. “Despite the improvement in today’s prostheses, they can’t necessarily take the weight,” he notes. He has suggested that many patients consider making an appointment at the
Emerson Center for Weight Loss. “Once they lose weight, they may feel less urgency about the need for joint replacement surgery,” he says. “Many people find they can postpone it until sometime later.”
