Tag Archives: obesity

Should There Be Strict BMI Cutoffs for TKA and THA?

happy senior couple hiking on the mountainDr. Stickney, a Kirkland orthopedic surgeon, is an expert in total knee arthroplasty, total hip arthroplasty, exercise and health, and more.

Recently we posted a blog about candidacy for and outcomes of Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA) in morbidly obese patients who underwent pre-operative weight loss. Operating on obese patients for TKA and THA continues to be a hot button topic of risk versus reward in surgical outcomes.

Two well-respected orthopedic authorities, recently faced off to have a deeper conversation about whether or not orthopedic surgeons should have strict BMI cutoffs for performing primary TKA or THA. Benjamin F. Ricciardi, MD engaged Thomas K. Fehring, MD, from OrthoCarolina and Nicholas Giori, MD and PhD, a Stanford University professor, to face off. Highlights are summarized below.

Q: To what degree does the evidence support a strict BMI cutoff to determine eligibility for primary TKA and THA?

Dr. Fehring noted many Americans (35%) are obese and the association between patients with a BMI above 40 and surgical complications/infection is irrefutable. He recommends looking at big data such as Medicare or Veterans Affairs, meta-analysis, and position statements by specialty medical societies. All findings to date underscore the need to have a strict cutoff, but Dr. Fehring noted it’s important to develop weight loss strategies for patients prior to arthroplasty. 

Dr. Giori agreed that obesity is undeniably related to complications, but BMI is a weak risk factor compared to others that are commonly accepted (such as heart and metabolic disorders).

Q: Given the expansion of strict BMI cutoffs at the administrative level, how should safety (non-maleficence) be balanced against access to care?

Dr. Giori said that while BMI cutoffs are well-intended, the ones currently used have the effect of arbitrarily rationing care without medical justification. Also, he feels it disproportionately affects minorities, women and patients in low socio-economic classes. In his opinion, the decision should be based on joint decision making between the doctor and the patient. Risk adjustments in payment models (for doctors’ compensation) would help in the future.

Dr. Fehring agreed with many of the points, but at a certain point the risk outweighs the benefit, and attempting to operate on all patients regardless of BMI becomes dangerous. Keeping his “do no harm” obligation in mind, Dr. Fehring stated a BMI cutoff of 40 as a reasonable goal for patient safety.

Q: If a patient with morbid obesity is to undergo arthroplasty, what steps should be taken before surgery to make hip or knee arthroplasty safer?

Dr. Fehring recommended the patient be in the best possible health they can be prior to elective surgery to avoid complications. An optimization program, factoring in body weight, blood glucose control, serum albumin, and smoking status are part of his clinic’s protocol; patients get tools to meet and stick to set goals before getting surgery. It’s not just about treating the knee or hip; it’s about treating the whole patient as well, he said.

Dr. Giori recognized that optimization programs can help and his clinic also offers one, but the best that can be done regarding obesity is encouragement and education, and referring the patient to a structured weight-reduction program. On the flipside, the patient should do his or her best to lose weight to get below a given BMI threshold. From there, doctor and patient can create a shared decision-making plan that may or may not involve surgery.

If you’d like to discuss weight concerns prior to your total knee or hip replacement surgery, please contact our office. We’ll help you return to your healthy, pain-free lifestyle.

Can Weight Loss Before Total Knee Arthroplasty Help?

Senior man having medical exam.When obese patients undergo total knee arthroplasty (TKA), many surgeons require or request preoperative weight loss. A group of researchers sought to determine the amount of weight loss needed in this patient population, to improve TKA operative time, length of stay, discharge to a rehab facility, and functional improvement after surgery. This is the first known study to look exclusively at obese patients to understand how preoperative weight loss might improve knee surgical outcomes after TKA.

Those considered morbidly obese have a body mass index (BMI) of 40 or higher. This study looked at 203 patients with a BMI of 40 or more. They were evaluated 90 days before their TKA, and again immediately preceding TKA, to assess weight loss. Of those who lost weight preoperatively, 41% had lost five or more pounds, 29% lost 10 or more pounds, and 14% lost 20 or more pounds.

Losing 10 or less pounds before surgery made no difference in operative time, length of stay, the need for discharge to a rehab facility, or post-operative functional improvement. However, the preoperative loss of 20 pounds or more showed benefits: It lowered the odds of discharge to a rehab facility, and was associated with a shortened length of stay. There were, however, no significant differences in surgery times or functional improvements for those who lost 20-plus pounds.

A longer stay in the hospital or discharge to a rehab facility is a driver of higher costs in primary total knee arthroplasty. Preoperative weight loss may reduce overall costs. The need for Discharge to a rehab facility is also correlated with an increased rate of post-operative infection. In the future, this study could help surgeons target a specific level of weight loss prior to TKA, for their patients to improve knee surgical outcomes.

If you’d like to discuss obesity or weight concerns prior to your total knee arthroplasty, or just want to learn more about the knee replacement procedure, please contact our office. We’ll help you return to your healthy, pain-free lifestyle.

Dr. Stickney, a Kirkland orthopedic surgeon, is an expert in total and partial knee arthroplasty, exercise and health, and more.