Incidence and timing of postoperative complications after total hip and knee arthroplasty

<h3>Background:</h3> Follow-up protocols after total hip or knee arthroplasty (THA or TKA, respectively) have little uniformity, which can lead to emergency department (ED) visits for postoperative complications. We sought to determine the incidence and timing of postoperative complications after THA or TKA. <h3>Methods:</h3> We conducted a population-based retrospective cohort study of all adults in Ontario who underwent primary THA or TKA between 2010 and 2019. We used data available through ICES. We identified medical and surgical complications, ED visits, and hospital readmissions using institutional databases and Ontario Health Insurance Plan claims. Outcomes included major medical complications within 30 days and surgical complications within 1 year after surgery. <h3>Results:</h3> We included 158 503 and 103 728 patients who underwent TKA and THA, respectively. The incidence of medical complications within 30 days was 2.90% after TKA and 2.42% after THA. Visits to the ED (20.0% after TKA, 16.9% after THA) and readmission rates within 30 days (3.8% after TKA, 4.1% after THA) were similar for both groups. Visits to the ED occurred at a median of 10 days after surgery for both groups, with readmissions at a median of 12 and 13 days after TKA and THA, respectively. The incidence of major TKA complications was 1.6%, with a median time of 84 (interquartile range [IQR] 26–224) days. The incidence of major THA complications was 2.2%, with a median time of 29 (IQR 16–80) days. <h3>Conclusion:</h3> Our findings suggest follow-up contact 7–10 days after THA or TKA to minimize ED visits, with at least 1 subsequent in-person follow-up at 5–6 weeks after surgery. After that, surgeons may personalize additional follow-ups as needed.