OBJECTIVES: For over fifty years, unicompartmental knee arthroplasty (UKA) has been used to treat single compartment osteoarthritis of the knee and is considered a safe alternative to total knee arthroplasty (TKA). The development and use of robotic-assisted surgery (r-UKA)* has made execution of the procedure more precise and various studies have reported improved radiographic outcomes and implant survival rates, however its cost-effectiveness is unknown. This study aimed to assess the cost-effectiveness of r-UKA compared to traditional unicompartmental knee arthroplasty (t-UKA) method in patients with unicompartmental knee osteoarthritis from the UK payer’s perspective.

METHODS: We developed a 5 year three Markov model to evaluate the expected costs and outcomes of the two strategies in patients aged 65 years. Failure rates for t-UKA were taken from the British National Joint Registry while data for r-UKA were obtained from a 2 year observational study. Cost were obtained from the NHS reference cost valued at 2018/19 GBP£ and a discount rate of 3.5% was applied to both costs and benefits.

RESULTS:For a high volume centre that performs 100 UKA operations per year, r-UKA was more costly than t-UKA but offered better clinical outcomes, the estimated cost per QALY was £2,831. The results were more favourable to younger patients aged less than 55 and sensitive to case volumes and follow up period.

CONCLUSIONS: r-UKA is cost-effective compared with t-UKA over a 5 year period. Results are dependent on case volumes, follow up period and favours younger age groups.

*NAVIO™ System (Smith & Nephew, Pittsburgh, PA, USA)