Patients with obesity benefit from joint replacement
Although patients with obesity are at higher risk for complications from joint replacement surgery, research suggests that these patients can still benefit greatly from these surgeries and that these surgeries remain cost-effective. Some studies have found that patients with obesity tend to have worse outcomes after surgery than patients who are not obese, but often, patients with high BMIs are starting from a lower point, with greater joint pain and limited mobility, Dr. Giori said. But the improvements – that is, net change in measured outcomes – can be greater for obese patients.
“Several studies have shown equal or greater improvements in validated outcome scores, function, and satisfaction compared with nonobese patients after surgery,” authors wrote in a recent review article in which they discuss how to optimize joint replacement surgery for patients with obesity. The article, published in the November 2022 issue of the Journal of the American Academy of Orthopaedic Surgeon (JAAOS), is part of a collection of review articles by the Movement Is Life Caucus.
Encourage weight loss, but look beyond the number
Rather than adhering to strict BMI cutoffs, some experts urge surgeons to consider the patient as a whole and to evaluate each individual’s overall health and potential risk. Dr. Giori generally considers high BMI as just another comorbidity when assessing a patient’s overall risk. “For a person who only has a high BMI but is otherwise healthy, I see no reason not to go ahead and schedule that person for surgery, because reducing the patient’s BMI will not substantially reduce the patient’s complication risk, and a delay in surgery may adversely affect the patient’s quality of life and ability to earn a living,” he said.
“If someone is between a BMI of 40 and 45, we are definitely going to have a discussion about weight,” Dr. Stronach said. He generally counsels against surgery for any patient with a BMI at 45 or above. He wants patients to have a BMI below 40 before surgery but considers individual cases for exceptions. “We will still move forward at times with someone with a BMI of 41, as an example, who is otherwise healthy,” he said. Similarly, if a patient has lost a significant amount of weight (e.g., the patient’s BMI was reduced from 50 to 41), the patient is actively engaged in improving their health, and surgeons believe the patient has significantly reduced their risk, “a lot of time, we’re not going to draw a line in the sand right at [a BMI of] 40,” he said.
While using a BMI of under 35 or 40 as a guideline when starting to work with patients is reasonable, working toward a weight loss of 5%-10% of total body weight is another goal to consider, authors advise in the JAAOS obesity review article. Research suggests that even a 5% reduction in overall body weight can reduce surgical complications and can improve a patient’s glucose and lipid levels and cardiac profile. Referrals to dietitians and weight loss programs, as well as behavioral counseling, can also be useful in initiating weight loss and keeping patients engaged in the process, the authors wrote.