Distinct Care Needs and Episodes of Care: Comparing Medical versus Orthopaedic Readmissions after Elective Primary Total Knee Arthroplasty.

Hospital readmissions after primary total knee arthroplasty (TKA) significantly drive health care expenditure and resource utilization. Recent studies have suggested differences between medical and orthopaedic readmissions after TKA and their episodes of care (EOCs) but lack patient-level data reporting. This study aimed to compare EOCs for medical and orthopaedic-related readmissions regarding initial readmission wards, services consulted, intensive care unit (ICU) admissions, blood transfusions, surgical interventions, length of stay, and discharge disposition.All patients enrolled in a prospective data collection system at a tertiary medical center undergoing elective, unilateral, primary TKA from 2016 to 2020 and readmitted within 90 days of discharge were included. Readmissions were categorized as related to medical or orthopaedic causes. Patients' electronic medical records were reviewed to collect demographic and clinical information about EOC associated with the readmission hospital course.In total, 82.4% (580/704) of 90-day readmissions after elective, primary TKA were related to medical causes, with the remaining 17.6% (124/704) of readmissions due to orthopaedic causes. Medical readmissions most often pertained to gastrointestinal complaints, while wound complications accounted for most orthopaedic readmissions. Most readmissions (63.1%, 444/704) occurred within the first 30 days after TKA. Patients with medical and orthopaedic readmissions had differences in EOC, such that more medical readmissions required ICU care (10.6 vs. 1.6%, p < 0.001), and more patients with orthopaedic readmissions needed a surgical intervention (65.4 vs. 6.7%, p < 0.001).By understanding differences in EOC for medical and orthopaedic readmissions after TKA, targeted initiatives can be developed to deliver more efficient, cost-effective orthopaedic surgical care, as the orthopaedic surgical community continues to provide value-based care.