The safety and cost-analysis of simultaneous versus staged bilateral total knee arthroplasty in a Taiwan population

Abstract The purpose of this study was to investigate the safety of Simultaneous, bilateral TKA (SiTKA). Furthermore, we also assessed the cost reduction of SiTKA in comparison with Staged, bilateral TKA (StTKA). We retrospectively review all patients that underwent SiTKA or StTKA due to osteoarthritis (OA) or spontaneous osteonecrosis of the knee (SONK).We assessed length of stay, transfusion rate, early postoperative complications, 30-day and 90-day readmission rate, 1-year reoperation rate and the indication for reoperation. Furthermore, we analyzed the total cost of the two groups, reimbursement from the national health insurance (NHI), cost of the procedures, and net income from each case. A total of 2016 patients (1565 SiTKA and 451 StTKAs) were included in this study. There were no significant differences in terms of complication rates, 30-day and 90-day readmission, and 1-year reoperations between the two groups. The total length of stay was on average 5.0 days longer for StTKA (p<0.01). In terms of cost, all categories of medical costs were significantly lower in SiTKA, while the net hospital income was significantly higher for StTKA. In conclusion, SiTKA and StTKA have similar postoperative complication, readmission and reoperation rates, while SiTKA significantly reduces medical expenses for the patient and NHI. Level of evidence: level III, retrospective cohort study