Increased Hospital Length of Stay for Obesity Class II and III Patients After Primary Total Ankle Arthroplasty: A NSQIP Analysis

Abstract

Category: Ankle Arthritis Introduction/Purpose: Obesity is a well-established risk factor for complications after total hip and knee arthroplasty. The incidence of total ankle arthroplasty (TAA) continues to grow, but few studies have evaluated TAA outcomes in patients with obesity. The present study sought to measure the impact of obesity on TAA outcomes using a national database. Methods: The 2012-2020 National Surgical Quality Improvement Program (NSQIP) database was queried for primary TAA (CPT:27002). 1,610 patients were identified and stratified by preoperative body mass index (BMI): non-obese (18 5-29.9kg/m 2 , n=760), obesity class I (30.0-34.9kg/m 2 , n=455), and class II and III (>35.0kg/m 2 , n=395). Preoperative and perioperative patient data, operative time, hospital length of stay (LOS), and 30-day complications were compared using univariable statistics. Multivariable analyses controlling for patient characteristics were employed to measure the effect of obesity on operative time and LOS. Results: Compared to the non-obese group, obesity class II and III patients were younger (61.9 versus 65.6 years;p < 0.001), more female (57.2% versus 42.0%;p < 0.001), higher ASA class (p < 0.001) and had more comorbidities such as hypertension, diabetes, and dyspnea (p < 0.001). Mean preoperative albumin was lower (p=0.013) and white blood count was higher (p < 0.001) in the obesity class II and III group. Home discharge rate was lowest in class II and III patients (88.6%;p=0.017). Multivariable regression revealed longer hospital LOS for obesity class II and III (μ=0.21; p=0.005) relative to the non-obese group. Obesity group was not associated with operative time or 30-day readmissions and reoperations. Conclusion: Obesity class II and III patients undergoing TAA had more comorbidities and longer hospital LOS compared to lower BMI patients. Despite the well-established association between obesity and postoperative complications after hip and knee arthroplasty, the present NSQIP analysis of 1,610 TAA patients did not find a greater burden of acute complications among patients with obesity.