Weight loss before surgery may not be beneficial for patients with knee osteoarthritis

A new study from the University of Alberta shows that losing weight before a new knee surgery does not lead to better outcomes for patients.

In a systematic study published in Bone marrow, Researchers at the Faculty of Rehabilitation Medicine have found that pre-surgery weight loss may not be beneficial for people with advanced knee osteoarthritis.

Medical doctors have advised patients to lose weight before surgery on his knee. Patients living with obesity, defined by a body mass index (BMI) of 30 or higher, are given special warning about complications of surgery, risk of infection and adverse outcomes due to the high BMI aca.

While there is evidence that a higher BMI equates to a potentially higher risk of surgery, that does not mean that if a patient reduces their BMI, even a point or two, it would be good for them. “

Kristine Godziuk, Lead Author, Postdoctoral Fellow, Department of Occupational Medicine, University of Alberta

The research team reviewed clinical practice guidelines and other literature with clinical impact from the past 10 years for evidence that weight loss is beneficial for patients. “We didn’t find any,” Godziuk said.

Osteoarthritis affects more than 300 million people worldwide, with the knee as the most commonly affected joint. Factors such as aging and obesity have increased the number of Canadians who have had knee replacements more than 22 percent in the past five years, with more than 75,000 surgeons now on board. their annual performance.

A U study of A raises a question about the use of BMI as a confirmation of patient outcomes for orthopedic surgery. For example, patients with a higher BMI are not eligible for relapses until they have reduced their BMI or lost weight. As a result, these patients spend more time on the waiting list, Godziuk said. Prior to the COVID-19 pandemic, waiting times for knee surgery in Alberta averaged between 14 months and two years.

“Patients with a higher BMI wait even longer because they are told to try to lose weight first, so before they come to surgery they are in a worse state than they would be. let them try that first. “

Weight bias is also at play. “It’s very challenging to lose weight and keep it off,” Godziuk said. Obesity is not a lifestyle choice but a debilitating condition that should not be measured by BMI, she said.

“We know that age is associated with an increased risk of surgery with knee replacement surgery, but we’re not telling people, ‘Well, you have to be younger than 70.’ We don’t make these cuts for age, but we do them for BMI, which ends up creating this bias in access to care. “

Not only does using BMI as a determinant limit access to surgery, Godziuk said, but it can endanger the health of patients, as short-term weight loss has few benefits that cannot be avoided. maintenance, and can be harmful.

“We tell patients to lose weight, reduce their BMI, but it can be harmful to get that broad recommendation. What we are proposing is that we may not tell them to lose weight. loss, but help them to prevent stress … That may be a better message to send to patients, through which we can also support them to improve body composition and overall health. “

Godziuk, who began her career as an exercise physicist, said working in pediatric obesity helped her understand that more research was needed in this area.

“I could see clinically, when I was working with teenagers, that BMI was a bad measure for them, and I know that it is a bad measure in adults. When we just relying on those simple metrics, I can see that this gap existed.And it is so important from a rehabilitation perspective – to help patients live with and manage osteoarthritis, including whether they also have obesity. “

Practitioners should be aware of the lack of evidence for weight loss before surgery and reconsider recommendations about BMI, Godziuk said.

“We do such a good job of looking deeper into other areas of a person’s health, but to pull obesity down to BMI, we miss some information.

“We’re not saying that everyone with a high BMI should have knee surgery, but we question the way it is assessed, that BMI alone misses some things. “