Background
Improved pain management and early mobilization protocols have increased interest in the feasibility of short stay (<24 hours) or outpatient total hip (THA) and total knee (TKA) arthroplasty. However, concerns exist regarding patient safety and readmissions. The purposes of this study were to determine the incidence of in-hospital complications following THA/TKA, to create a model to identify comorbidities associated with the risk of developing major complications >24 hours postoperatively, and to validate this model against another consecutive series of patients.