BMI a valuable metric in THA surgical planning, risk stratification

Editor's Note

Obesity is a key driver of earlier total hip arthroplasty (THA) and elevated perioperative risk, according to findings published October 29 in Surgeries. While THA is a well-known intervention for older adults with end-stage hip osteoarthritis, the researchers reported a link between an increase in obesity and the need for THA at a younger age, accompanied with a higher risk for worse postoperative outcomes.

They conducted a retrospective analysis of 1,626,965 elective THA hospitalizations from the Nationwide Inpatient Sample to understand the primary determinants of THA across various BMI categories, including <29.9, 30–34.9, and ≥35. The research examined the prevalence and impact of comorbidities on postoperative complications and analyzed differences in hospital length of stay, healthcare costs, and mortality rates among the different BMI groups.

They found that higher BMI was significantly associated with younger age at THA. Specifically, they found that each 5-unit BMI increase corresponded to a ~2-year decrease in age at surgery. Obese patients in the study had higher rates of hypertension, diabetes, dyslipidemia, and sleep apnea prior to surgery, and experienced postoperative blood loss anemia, acute kidney injury, venous thromboembolism, and postoperative infections. Additionally, length of stay increased with BMI. However, total hospital charges demonstrated minimal clinical variation, per the report. 

The investigators concluded that obesity is a key driver of earlier THA and elevated perioperative risk. Therefore, they suggested that BMI should be a factor in creating surgical planning and risk stratification prior to surgery. They also suggested that for younger, high-BMI THA patients, preoperative optimization, complication prevention, and long-term implant durability should be considered.