COST-UTILITY ANALYSIS OF ROBOTIC AND CONVENTIONAL TOTAL KNEE ARTHROPLASTY: A 200-PATIENT MICRO-COSTING STUDY IN A PUBLIC SECTOR INSTITUTION

Background Robotic-arm assisted total knee arthroplasty (RO TKA) has been introduced to enhance the accuracy and consistency of knee replacement surgery compared with traditional methods. Despite these potential advantages, the financial impact of implementing robotic systems remains unclear, particularly in publicly funded healthcare settings. This study evaluates the in-hospital costs and health-related quality of life outcomes of RO TKA compared with conventional total knee arthroplasty (CO TKA) using a cost-utility approach within a UK National Health Service (NHS) hospital. Methods A propensity-matched cohort cost-utility analysis was conducted including 200 patients undergoing primary TKA for advanced osteoarthritis at a high-volume tertiary centre. Patients were matched 1:1 by age, sex, and American Society of Anesthesiologists (ASA) grade, with 100 undergoing RO TKA and 100 undergoing CO TKA. Direct hospital costs were calculated using a micro-costing methodology. Health-related quality of life was assessed using the EQ-5D-3L questionnaire before surgery and at one year postoperatively to estimate quality-adjusted life years (QALYs). The primary outcome measure was the incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses were performed to evaluate the robustness of the results. Results Average in-hospital costs were slightly higher for RO TKA compared with CO TKA (£6,517 vs £6,204), corresponding to an additional £313 per patient. However, the RO TKA group experienced a significantly shorter hospital stay (2.3 vs 3.1 days; p = 0.008) along with reduced ward-related (p = 0.029) and drug and pharmacy (p = 0.041) costs. One year after surgery, patients who underwent RO TKA reported higher EQ-5D-3L scores (0.82 vs 0.75; p < 0.001), leading to a greater average QALY gain (0.192 vs 0.140). The incremental QALY improvement of 0.052 resulted in an ICER of £6,019 per QALY gained, which is substantially below the National Institute for Health and Care Excellence (NICE) willingness-to-pay threshold of £20,000–£30,000 per QALY. Sensitivity analyses supported the stability of these findings. Conclusions Robotic-arm assisted TKA was associated with improved postoperative health utility and demonstrated cost-effectiveness despite slightly higher initial costs. These findings suggest that RO TKA represents a clinically beneficial and economically reasonable advancement for knee arthroplasty within a publicly funded healthcare system.