The prevalence of obesity and morbid obesity in the U.S. has reached record levels, with over 50% of adults affected. Obese patients undergoing total joint arthroplasty (TJA) face increased post-operative complications, yet studies on optimizing outcomes for this population are limited. The COVID-19 pandemic accelerated the shift towards same-day discharge (SDD) for TJA, but the impact on morbidly obese patients remains understudied. This study aims to fill this gap by examining outcomes and costs for morbidly obese patients undergoing SDD TJA.
This study is a retrospective review of the PearlDiver Mariner Database. Based on the procedure and their body mass index (BMI), the patients were divided into 4 SDD groups: Total knee arthroplasty (TKA)-BMI > 40, TKA-BMI  40, and THA-BMI < 40. The two TKA groups were matched based on age, gender, and the Charlson comorbidity index (CCI). The THA groups were matched similarly. Outcomes at 30 and 90 days post-operatively were compared between the groups.
5588 patients were included in each TKA group, and 1675 patients in each THA group. When compared to individuals with a BMI of less than 40, patients with morbid obesity receiving SDD TKA had greater incidence of deep vein thrombosis (DVT) (p < 0.05), urinary tract infection (UTI) (p < 0.05), readmissions (p < 0.05), superficial surgical site infection (SSSI) (p < 0.05), and higher costs (p < 0.05). Regarding SDD THA, patients with morbid obesity had greater incidence of DVT (p < 0.05), UTI (p < 0.05), emergency department visits (p < 0.05), readmissions (p < 0.05), intensive care unit admission (p < 0.05), prosthetic joint infection (p < 0.05), SSSI (p < 0.05), and higher costs (p < 0.05).
This study highlights the considerable challenges faced by morbidly obese patients undergoing SDD TJA. Patient optimization prior to undergoing total joint replacement may benefit morbidly obese patients undergoing same day discharge. Further research is needed.

© 2025. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.