ICL encourages surgeons to shift focus from BMI, consider factors surrounding obesity and weight loss

Patients such as Lynn Rubinett have been failed by the system. 

Rubinett shared her experience during Monday’s ICL panel discussion “Beyond the Scale: Exploring Controversies Related to Obesity, Weight Loss, and Total Joint Arthroplasty,” where surgeons and researchers examined the nuances, confounders, and limited evidence surrounding BMI restrictions and the impact that a patient’s preoperative weight has on total joint arthroplasty (TJA) outcomes. 

In her early 60s, Rubinett had a BMI ≥ 40, and advanced osteoarthritis that left her in severe pain as she became increasingly immobile. She needed a total hip replacement, but finding a surgeon willing to perform the surgery was a challenge.

“I was told by one surgeon I was not eligible for surgery because of my BMI, and another surgeon told me to lose 50 pounds and come back in a year,” Rubinett shared. “Finally, the third orthopaedic surgeon pulled back the curtain and told me that all the orthopedic surgeons in the area had agreed upon a mandatory BMI cutoff of ≥ 40.”

Rubinett ultimately found a pathway to surgery through an individualized review process. Still, her experience underscores the controversy surrounding the BMI cutoff for TJA — a policy that is often adopted by payers and is not supported by current evidence. 

Obesity and BMI’s impact on surgical outcomes
“It is important to remember that obesity and BMI are not the same thing,” said Nicholas J. Giori, MD, PhD, FAAOS, chief of orthopaedic surgery at Stanford Medicine. “Obesity is a chronic medical condition, and high BMI is simply a ratio of weight to height squared.”

Dr. Giori highlighted that administratively mandated BMI restrictions create “a virtually insurmountable barrier” for many patients who could benefit from surgery. 

“These restrictions should be eliminated, and surgeons should assess their own skills and tolerance to risk in an open discussion with their patient through shared decision making,” Dr. Giori explained. “There is no evidence demonstrating that mandating a patient meet an arbitrarily chosen weight loss goal does anything to reduce risk, and in my opinion, it is a form of weight bias.”

He reviewed data suggesting that modest preoperative weight loss (5% or more) does not consistently reduce surgical site infections or readmissions. Some database studies have even shown higher complication rates among patients who lost weight before surgery. The current evidence supporting mandated weight loss remains low quality.

Look beyond the scale
Kristine Godziuk, PhD, assistant professor in the Department of Physical Therapy and Rehabilitation Science at the University of California, San Francisco, and a member of the Advisory Committee Co-Designing Solutions Regarding Obesity and Arthroplasty, urged orthopaedic surgeons to look beyond the number on the scale.

As more patients turn to GLP-1 medications or bariatric surgery to lose weight before TJA, the evidence remains unclear. “There are many confounders that we need to study, and this is why the evidence is so murky,” Dr. Godziuk said, noting that how weight is lost, how quickly it is lost, and changes in body composition all matter.

Rapid weight loss, particularly with GLP-1 medications, can lead to significant muscle loss, increased risk of malnutrition, and potential bone density decline, especially in older adults. Dr. Godziuk highlighted growing concerns about sarcopenic obesity (high fat mass with low muscle mass and strength) and osteosarcopenic obesity, which also includes poor bone quality — conditions that may increase frailty and surgical risk.

“We need to have honest conversations with patients,” Dr. Godziuk added. “While weight loss may help some individuals, its effect on surgical outcomes is still uncertain, and potential risks — particularly muscle, bone, and nutritional decline — must be part of the discussion.”

Experience matters in surgical outcomes
Anna Cohen-Rosenblum, MD, MSc, FAAOS, orthopaedic surgeon at NYU Langone Health, reviewed operative considerations for patients of larger body size. She also discussed emerging data that suggest surgeon experience plays a critical role. Higher-volume surgeons and those who more frequently operate on patients with higher BMI tend to have lower complication and revision rates, including reduced prosthetic joint infection.

Jennifer Lefkowitz is a freelance writer.