Body Mass Index is a Predictor of Discharge to a Post-Acute Care Facility Following Total Ankle Arthroplasty

Abstract

Category: Ankle Introduction/Purpose: The utilization of total ankle arthroplasty (TAA) continues to increase, and identifying preoperative factors that influence postoperative outcomes after TAA may be valuable. The use of post-acute care (PAC) facilities has also grown substantially, and discharge to a PAC facility can increase patient morbidity and postoperative costs. The purpose of this study is to define the effect of BMI on discharge to a PAC facility and hospital length of stay (LOS) following TAA. Methods: We performed a retrospective review to identify a large cohort of adult patients who underwent TAA between 2006 - 2020 from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Using overweight patients as the reference BMI group, we estimated a sex- and age- adjusted log-binomial regression model on BMI categories to estimate risk ratios to analyze the association between BMI and risk of being discharged to a PAC facility and/or hospital LOS. Results: Relative to overweight patients, obese patients had 1.47 times the risk (P=0.008), and morbidly obese patients had 2.26 times risk (P < 0.001) of being discharged to a PAC facility after TAA. Males had 0.47 times the risk of females (P < 0.001), and for each year older, patients had 1.07 times the risk (P < 0.001) of being discharged to a PAC facility. There was no difference in hospital LOS for underweight patients, but healthy weight patients stayed an additional 0.29 days (P=0.004), obese patients stayed an additional 0.18 days (P=0.010), and morbidly obese patients stayed an additional 0.34 days (P=0.006). Males stayed 0.30 fewer hospital days than females (P < 0.001), and for each year older, patients stayed 0.011 days longer (P < 0.001). Conclusion: This study found that women and patients who are obese and morbidly obese have a greater LOS and chance to be discharged to a PAC facility. Increasing age is also associated with an increase in LOS and discharge to a PAC. These may be important factors when discussing the postoperative plan with patients prior to TAA.