Early Economic Analysis of Robotic-Assisted Unicondylar Knee Arthroplasty May Be Cost Effective in Patients with End-Stage Osteoarthritis.

Unicondylar knee arthroplasty (UKA), as an alternative to total knee arthroplasty (TKA), has been shown to be an effective option for patients with single-compartment end-stage knee osteoarthritis. Implant survival is contingent upon proper alignment, which has been improved with the advent of robotic-assisted surgery (r-UKA), but whether this outweighs the increased cost of the robotic-assist device has not been analyzed in the literature. The purpose of this study was to investigate the mid-term cost-effectiveness of r-UKA compared with UKA with traditional instrumentation (t-UKA) in the United States. A cost-effectiveness analysis using a four-state Markov model was performed using data from the 2018 National Joint Registry of England and Wales and a retrospective multicenter, cohort study on a cohort of 65-year-old patients having undergone r-UKA. The main outcome was cost per revision avoided and sensitivity analyses were conducted to evaluate the impact of using different model assumptions on the results. The Markov model illustrated that the benefit derived from r-UKA versus t-UKA was beneficial from a payer's perspective. The estimated incremental cost-effectiveness ratio (ICER) was $14,737 per revision avoided in a facility seeing 100 patients a year. Case volume was shown to be the primary variable affecting cost-effectiveness, with the value of r-UKA directly increasing with higher case volumes. Cost-effectiveness analyses demonstrated that the use of r-UKA is an effective alternative to t-UKA in patients with single-compartment knee osteoarthritis. While this study could benefit from longer follow-up clinical studies to illustrate the benefits of r-UKAs beyond the current 2 years time horizon, r-UKAs remained cost-effective, even after investigating several different assumptions.