BACKGROUND: The Comprehensive Care for Joint Replacement Model, developed by Centers for Medicare and Medicaid Services, aims to improve the quality of joint replacement. Metrics including emergency room visit rates after primary total knee and total hip arthroplasty (TKA and THA) are of particular interest. The purpose of this study is to determine if preoperative emergency department (ED) visits are predictive of postoperative ED visits among patients undergoing elective THA or TKA. METHODS: In a retrospective analysis of 6996 patients who underwent elective primary arthroplasty (2453 hips, 4543 knees), we identified all patients who had an ED visit from up to 1 year prior to their surgical date to 90 days after. We assessed if preoperati...