Osteoarthritis and Osteonecrosis in Total Hip Arthroplasty: 90-Day Postoperative Costs and Outcomes

Background: Two common diagnoses for patients undergoing total hip arthroplasty (THA) are osteoarthritis (OA) and osteonecrosis (ON), pathologically different diseases that affect postoperative complication rates. The underlying pathology of ON may predispose patients to a higher rate of certain complications. Previous research has linked ON with higher mortality and revisions, but a comparison of costs and complication rates may help elucidate further risks. This study reports 90-day costs, lengths of stay (LOS), readmission rates, and complication rates between patients undergoing THA for OA and ON. Methods: The Nationwide Readmissions Database was retrospectively reviewed for primary THAs, with 90-day readmissions assessed from the index procedure. Patients diagnosed with OA (n = 1,577,991) and ON (n = 55,034) were identified. Costs, LOS, and any readmission within 90 days for complications were recorded and analyzed with the chi-square and t-tests. Results: Patients with ON had higher 90-day costs ($20,110.80 vs. 22,462.79, P <.01) and longer average LOS (3.48 vs. 4.49 days, P <.01). Readmission rates within 90 days of index THA were significantly higher among patients with ON (7.7% vs. 13.1%, P <.01). Patients with OA had a lower incidence of 90-day overall complications (4.1 vs. 6.4%, P <.01). Conclusions: Patients undergoing THA for ON incur higher readmission- related costs and complication rates. Understanding the predisposing factors for increased complications in ON may improve patient outcomes. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

Patients undergoing THA for osteonecrosis (ON) incur higher readmission-related costs and complication rates compared to patients with osteoarthritis (OA), as evidenced by higher 90-day costs, longer lengths of stay, and higher readmission rates within 90 days for ON patients. Understanding the predisposing factors for increased complications in ON may lead to improved patient outcomes.