Simultaneous versus Staged Bilateral Oxford Unicompartmental Knee Arthroplasty in the Era of Diagnosis-related Group: Influence on Outcome and Costs of Care

Abstract Background: Bilateral knee osteoarthritis management with Oxford unicompartmental knee arthroplasty (OUKA) has demonstrated promising survival rates. Simultaneous OUKA optimizes costs and recovery but may increase perioperative risks, whereas staged OUKA allows for controlled recovery in high-risk patients. Comparable outcomes necessitate patient-specific approaches that emphasize the importance of diagnosis-related group (DRG)-driven cost efficiency in healthcare resource allocation. Objectives: This study aimed to evaluate the safety, functional and radiographic outcomes, complications, and potential DRG bonuses in simultaneous bilateral OUKA compared with staged bilateral OUKA. Materials and Methods: A retrospective cohort study was conducted on 37 patients with bilateral knee osteoarthritis (74 knees) treated by a single surgeon at a single medical center between 2019 and 2024. Functional outcomes were assessed using the Knee Society Score. The DRG of a single admission period and complications within 30 days were documented. Results: Patient demographics, comorbidities, and perioperative factors showed no significant differences between the simultaneous and staged OUKA groups, except for greater hemoglobin reduction in the simultaneous group ( P < 0.0001). Functional scores and implant parameters were comparable between groups. Simultaneous procedures resulted in lower hospital costs ( P < 0.0001) and higher DRG bonuses ( P = 0.008) than those of staged procedures. Conclusions: Simultaneous bilateral OUKA did not lead to increased complication rates or worsened functional scores. Moreover, it offers the benefits of shorter hospital stays and increased DRG bonuses.