Should Total Hip Arthroplasty Surgeons Be Concerned that a Delay Between the Date of Surgical Booking and Surgery Influences Patient Body Mass Index and Short-Term Outcomes?

Abstract

Obesity is a known risk factor for complications after total hip arthroplasty (THA), with societal guidelines recommending surgical delay for patients above body mass index (BMI) targets. Consequently, patients are motivated to reach BMI targets before the office visit, discussing surgical booking. Our study investigates BMI fluctuations between surgical booking and the surgery date and whether these fluctuations have implications for peri- and postoperative outcomes. We retrospectively reviewed our institutional database for elective, primary, unilateral THA from 2015 to 2024 with a minimum 90-day follow-up. The cohort was stratified into three groups by percent BMI change from booking date to THA date: Group 1, decrease in BMI; Group 2, 0 to 5% increase in BMI; and Group 3, > 5% increase in BMI. Baseline demographic factors, as well as peri- and postoperative outcomes, were compared. A multivariate regression analysis evaluated risk factors for interval change in BMI. We reviewed 10,400 THA patients who had an average 62-day delay between booking and surgery dates, where 44.2, 42.2, and 13.6% were allocated to Groups 1, 2, and 3, respectively. Operative time, length of stay, and discharge to a rehab facility were significantly higher in Group 3 compared to the others. There were no significant differences seen in 90-day outcomes, including emergency department (ED) visits, readmissions, or revision rates. Multivariate regression analyses identified that elevated BMI at the time of surgery predicted increased septic revision incidence (OR [odds ratio]: 1.1, P < 0.001). Surgical delay and BMI change between booking and surgery did not influence all-cause and septic revision rates. Our study is the first to evaluate preoperative BMI fluctuations between the booking date and surgery date. We found that most patients (55.8%) gained weight, with 13.6% increasing > 5% BMI. Importantly, these weight changes do not impact short-term complications or revision rates, comforting THA surgeons who see interval weight gain on the day of surgery.