Cost-effectiveness analysis of robotic-arm assisted total knee arthroplasty.

PURPOSE: Total knee arthroplasty (TKA) is widely recognized as an effective treatment for end-stage knee osteoarthritis (OA). Compared with conventional TKA, robotic-arm assisted TKA may improve patients' functionality and resulting quality of life by more accurate and precise component placement. Currently, the literature on cost-effectiveness of robotic-arm assisted TKA in the US is limited. The objective of this study was to assess the cost-effectiveness of robotic-arm assisted TKA relative to TKA in the Medicare-aged population including exploring the impact of hospital volume on cost-effectiveness outcomes.

METHODS: We developed a decision-analytic model to evaluate the costs, health outcomes, and incremental cost-effectiveness ratio (ICER) of robotic-arm assisted TKA vs TKA in Medicare population with OA. We evaluated cost-effectiveness at a willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life-year (QALY). We sourced costs from the literature including episode-of-care (EOC) costs from a Medicare study. We assessed cost-effectiveness of robotic-arm assisted TKA by hospital procedure volume and conducted deterministic (DSA) and probabilistic sensitivity analysis (PSA).

RESULTS: For the average patient treated in a hospital with an annual volume of 50 procedures, robotic-arm assisted TKA resulted in a total QALY of 6.18 relative to 6.17 under conventional TKA. Total discounted costs per patient were $32,535 and $31,917 for robotic-arm assisted TKA and conventional TKA, respectively. Robotic-arm assisted TKA was cost-effective in the base case with an ICER of $41,331/QALY. In univariate DSA, cost-effectiveness outcomes were most sensitive to the annual hospital procedure volume. Robotic-arm assisted TKA was cost-effective at a WTP of $50,000/QALY only when hospital volume exceeded 49 procedures per year. In PSA, robotic-arm assisted TKA was cost-effective at a $50,000/QALY WTP threshold in 50.4% of 10,000 simulations.

CONCLUSIONS: Despite high robotic purchase costs, robotic-arm assisted TKA is likely to be cost-effective relative to TKA in the Medicare population with knee OA in high-volume hospitals through lowering revision rates and decreasing post-acute care costs. Higher-volume hospitals may deliver higher value in performing in robotic-arm assisted TKA.