Medical Causes Account for 75% of Readmissions After Primary Total Hip Arthroplasty: Differences in Episodes of Care

Recent reports have suggested that readmissions due to medical or orthopaedic surgical causes after total hip arthroplasty (THA) differ regarding risk factors and cost. Further work is needed to elucidate explanations for cost differences to develop targeted initiatives for improved quality of care and health care utilization surrounding THA. This study aimed to determine differences in episodes of care (EOC) between patients readmitted within 90 days of THA for medical and orthopaedic causes.

The study included all patients who underwent elective, unilateral, primary THA at a tertiary medical center from 2016 to 2020 and were subsequently readmitted within 90 days. Readmissions were classified as related to medical or orthopaedic surgical causes. Demographic and clinical information related to the EOC for the readmission hospital stay was collected.

The 90-day readmission rate after THA was 5.6% (502 of 8,893 patients), with 75.1% (377 of 502) related to medical causes and 24.9% (125 of 502) related to orthopaedic causes. The EOC between the two groups differed in several ways. Patients readmitted for medical causes more frequently required intensive care unit admissions (12.0 versus 4.9%, P = 0.024), while a larger proportion of patients who had orthopaedic-related readmissions required blood product transfusions (36.3 versus 12.0%, P < 0.001), minimally invasive procedures (34.4 versus 18.9%, P < 0.001), and surgical interventions (79.2 versus 7.2%, P < 0.001).

Understanding differences in readmission EOC related to medical and orthopaedic causes after THA can help optimize health care allocation strategies and inform targeted quality improvement initiatives. As the demand for THA grows and reimbursement declines, insights into the predominance of medical readmissions and key differences in EOC are crucial for enhancing the quality and cost-effectiveness of THA care delivery models.