The Cost-Effectiveness of Robotic-Assisted Versus Manual Total Knee Arthroplasty: A Markov Model-Based Evaluation

Introduction: The purpose of this study was to investigate the cost-effectiveness of robotic-assisted total knee arthroplasty (TKA) versus conventional manual TKA in patients with knee osteoarthritis.

Methods: A Markov model simulated the lifetime outcomes of TKA of patients at average age 60 years. Costs of robotic-assisted TKA included a preoperative CT scan and the costs for acquisition and use of robotic equipment (average $706,250). We used three institutional case volumes to generate average per-case robotic costs: low volume (10 cases, $71,025 per case), mid volume (100 cases, $7,463 per case), and high volume (200 cases, $3,931 per case). Systematic reviews were used to determine early (≤1 year) and late (> 1 year) revision rates after robotic-assisted TKA (0.3 and 0.6%, respectively) and conventional TKA (0.78% and 1.5%, respectively). Outcomes were total costs and health outcomes measured in quality-adjusted life-years (QALYs). Costs and QALYs were organized into incremental cost-effectiveness ratios (ICERs). A procedure was considered cost-effective if its ICER fell below willingness-to-pay (WTP) thresholds of $50,000 and $100,000/QALY. Sensitivity analyses evaluated the effect of data uncertainty.

Results: Robotic-assisted TKA produced 13.55 QALYs versus 13.29 QALYs for conventional TKA. Total costs per case for robotic-assisted TKA were $92,823 (low volume), $29,261 (mid volume), and $25,730 (high volume) compared with $25,113 for conventional. The ICERs for robotic-assisted TKAs were $256,055/QALY (low volume), $15,685/QALY (mid volume), and $2,331/QALY (high volume). ICERs for mid- and high-volume institutions were below WTP. Average number needed to treat was >42 and >24 robotic-assisted TKAs for cost-effectiveness at the $50,000 and $100,000/QALY WTP. Robotic-assisted TKAs remained cost-effective when annual revision rates <1.6% and quality of life values were >0.85.

Conclusion: With lower annualized revision rates and higher postoperative quality of life, robotic-assisted TKAs potentially offer improved health outcomes, especially when annual institutional case volume >24 cases per year. Continued prospective investigation will be crucial to demonstrate the value of this new technology.