The Key to Meet BMI Cutoff for Orthopedic Surgery?

The woman, in severe pain from hip and knee osteoarthritis, was confined to a wheelchair and had been told that would likely be for life. To qualify for hip replacement surgery, she needed to lose 100 lb, a seemingly impossible goal. But she wanted to try.

“We tried a couple of medicines — oral medicines off-label — topiramate, phentermine,” said Leslie Golden, MD, MPH, DABM, a family medicine physician and obesity medicine specialist in Watertown, Wisconsin, 42 miles northeast of Madison.

They weren’t enough. But then Golden turned to glucagon-like peptide 1 (GLP-1) receptor agonists, and they delivered.

“She did lose a significant amount of weight and was able to get the hip replacement,” said Golden.

It took a couple of years. However, seeing her walk into her office, rather than wheel in, “is still one of the joys of my practice,” Golden said. “She’s so grateful. She felt everyone else had written her off.”

As she told Golden: “If I fell and broke my leg today, they would take me to surgery without concern.”

Because her hip replacement was viewed as a nonemergency procedure, the accepted threshold for elective safe surgery was a body mass index (BMI)

Golden is at the forefront of a growing trend — obesity medicine physicians collaborating with surgeons to prescribe the more effective GLP-1s and get surgery candidates to the starting line. She worked with Rajit Chakravarty, MD, an adult reconstructive surgeon who practices in Watertown and nearby Madison, to oversee the weight loss.

High BMIs & Surgery Issues

High BMIs have long been linked with post-surgery complications, poor wound healing, and other issues, although some research now is questioning some of those associations. Even so, surgeons have long stressed weight loss for their patients with obesity before orthopedic and other procedures.

These days, surgeons are more likely to need to have that talk. In the last decade, the age-adjusted prevalence of severe obesity — a BMI of ≥ 40 — has increased from 7.7% to 9.7% of US adults. The number of joint replacements is also rising — more than 700,000 total knee arthroplasty (TKA) and more than 450,000 total hip arthroplasty (THA), according to the American Academy of Orthopaedic Surgeons. As the population ages, those numbers are expected to increase.

Making the GLP-1 Choice

GLP-1s aren’t the only choice, of course. But they’re often more effective, as Golden found, than other medications. And when his patients with obesity are offered bariatric surgery or GLP-1s, “people definitely want to avoid the bariatric surgery,” Chakravarty said.

With the US Food and Drug Administration (FDA) approval of semaglutide (Wegovy) in June 2021 for chronic weight management and then tirzepatide (Zepbound) in November 2023, interest has boomed, he said, among his surgery candidates with a high BMI.

The FDA approved Wegovy based on clinical trials, including one in which participants lost an average of 12.4% of initial body weight compared with those on placebo. It approved Zepbound based on clinical trials, including one in which those on Zepbound lost an average of 18% of their body weight compared with those on placebo.

The wheelchair-bound woman, now 65, began with a BMI of 63, Golden said. She negotiated a cutoff of 45 with the surgeon and got the go-ahead. Currently, her BMI is 36 as she stayed on the medications.

Beyond the benefit of GLP-1s helping patients meet the BMI cutoff, some research finds fewer postoperative infections and readmissions with their use. This study found the medications did lower both, and another found reduced readmissions and complications.

Growing Partnerships, Increasing Success

Helping patients lose weight isn’t just about lowering the BMI, Chakravarty pointed out. The aim is to improve nutritional health — to teach patients how to eat healthfully for their needs, in turn improving other health barometers. Referring them to an obesity medicine physician helps to meet those goals, he said.

When Daniel Wiznia, MD, a Yale Medicine orthopedic surgeon and co-director of the Avascular Necrosis Program, has a patient who must delay a TKA or THA until they meet a BMI cutoff, he refers that patient to the Yale Medicine Center for Weight Management, New Haven, Connecticut, to learn about weight loss, including the options of anti-obesity medications or bariatric surgery.

Taking the GLP-1s can be a game changer, according to Wiznia and John Morton, MD, MPH, FACS, FASMBS, Yale’s medical director of Bariatric Surgery and professor and vice chair of surgery, who is a physician-director of the center. The program includes other options, such as bariatric surgery, and emphasizes diet and other lifestyle measures. GLP-1s give about a 15% weight loss, Morton said, compared with bariatric surgery providing up to 30%.

Sarah Stombaugh, MD, a family medicine and obesity medicine physician in Charlottesville, Virginia, often gets referrals from two orthopedic surgeons in her community. One recent patient in her early 60s had a BMI of 43.2, too high to qualify for the TKA she needed. On GLP-1s, the initial goal was to decrease a weight of 244 to 225, bringing the BMI to 39.9. The woman did that, then kept losing before her surgery was scheduled, getting to a weight of 210 or a BMI of 37 and staying there for 3 months before the surgery.

She had the TKA, and 5 months out, she is doing well, Stombaugh said. “We do medical weight loss primarily with the GLP-1s because they’re simply the best, the most effective,” Stombaugh said. She does occasionally use oral medications such as naltrexone/bupropion (Contrave).

Stombaugh sees the collaborating trend as still evolving. When she attends obesity medicine conferences, not all her colleagues report they are partnering with surgeons. But she predicts the practice will increase, saying the popularization of what she terms the more effective GLP-1 medications Wegovy and Zepbound is driving it. Partnering with the surgeon requires a conversation at the beginning, when the referral is made, about goals. After that, she sees her patient monthly and sends progress notes to the surgeon.

Golden collaborates with three orthopedic groups in her area, primarily for knee and hip surgeries, but has also helped patients meet the BMI cutoff before spine-related surgeries. She is helping a lung transplant patient now. She has seen several patients who must meet BMI requirements before starting in vitro fertilization, due to the need for conscious sedation for egg retrieval. She has had a few patients who had to meet a BMI cutoff for nonemergency hernia repair.

Insurance Issues

Insurance remains an issue for the pricey medications. “Only about a third of patients are routinely covered with insurance,” Morton of Yale said.

However, it’s improving, he said. Golden also finds about a third of private payers cover the medication but tries to use manufacturers’ coupons to help defray the costs (from about $1000 or $1400 to about $500 a month). She has sometimes gotten enough samples to get patients to their BMI goal, she said.

Morton consulted for Novo Nordisk, Eli Lilly and Company, Olympus, Teleflex, and Johnson & Johnson.