Study finds knee replacement surgery may lead to weight gain

Patients who undergo knee replacement surgery may be at risk of gaining more weight than their peers who have not had the surgery, according to a five-year study led by a Virginia Commonwealth University professor.

Daniel Riddle, Ph.D., professor in the VCU Department of Physical Therapy in the School of Allied Health Professions, and his research team reviewed the medical records of nearly 1,000 knee-replacement surgery patients from the Mayo Clinic Health System and found that 30 percent of them gained 5 percent or more of their body weight in five years following surgery.

In a comparison group of people who had not had surgery, only 20 percent gained equivalent amounts of weight during the same period.

"Part of the explanation is that people may have spent years adapting to their circumstances by avoiding activities that could cause knee pain," Riddle said. "We need to encourage patients to take advantage of their ability to function better and offer strategies for weight loss or weight management."

The study also shows that preoperative weight loss is a risk factor that frequently leads to weight gain following the procedure.

Overweight and obese patients preparing for surgery are frequently encouraged to lose weight prior to surgery to aid in enhancing early recovery and reduce the risk of complications.

"The subsequent weight gain potentially puts patients at risk of developing chronic health conditions, such as cardiovascular disease or diabetes," said Riddle.