Robotic vs. Conventional Surgical Approaches in Hospital Outpatient Department Total Knee Arthroplasty: A Value-Comparative Study

Introduction: U.S. healthcare costs have ranked highest among developed nations, emphasizing the need to increase cost-effectiveness while maintaining quality of care.1 Studies have compared cost-effectiveness of robotic versus conventional total knee arthroplasty (TKA), but none through Time-Driven Activity-Based Costing (TDABC) methodology.2 This study compares the value of conventional and robot-assisted TKA performed in hospital-based outpatient department (HOPD) settings. Methods: Total costs were calculated using TDABC, activity-based supply costing (ABC), and claims-based facility costs. The time each personnel spent per patient was multiplied by their per-minute salary to determine direct variable labor costs. Differences in pre-operative and 6-month post-operative Knee Injury and Osteoarthritis Outcome Score – Joint Replacement (KOOS-JR) scores were multiplied by average life-years remaining for each patient to determine KOOS-JR-adjusted life-years (KALYs). Costs were divided by KALYs to determine average cost-effectiveness ratios (ACER). Results: 22 patients undergoing conventional TKA and 21 undergoing robotic TKA were recruited. In conventional TKA, the average cost was $32,383.06, while the average cost of robotic TKA was insignificantly higher at $34,023.12 (p=0.60). The average KALY for the conventional surgeries was 1.89 while the robotic KALY average was 1.88 (p=0.984). Overall, the average ACER for conventional TKA ($17,089.87/KALY) was less than the average ACER for robotic TKA ($18,230.80/KALY). Conclusion: Conventional TKA in HOPD has insignificantly lower costs with comparable outcomes than robotic TKA in HOPD. Comparing ACER values shows that conventional TKA in HOPD is marginally more cost-effective than robotic TKA, mainly driven by the slight cost reduction of the conventional TKA procedure.