Summary

Robot-assisted TKA might be a cost-effective procedure compared to conventional TKA if a minimum of 253 cases are performed on a yearly basis, based on the assumption of higher revision rates in case of coronal malalignment.

Abstract

Background

A rising prevalence of knee osteoarthritis is leading to an increase in total knee arthroplasties (TKA) performed worldwide. The accompanying revisions pose an increasing economic burden on health care systems. Robot-assisted (RA) TKA has been developed to improve revision rates due to component malalignment and soft tissue imbalance.
With this study, the authors aim to prove a theoretical, preliminary cost-effectiveness analysis of RA TKA.

Methods

A Markov state-transition model was designed to evaluate the health status of a 67-year-old with knee osteoarthritis undergoing TKA over a 20 year time period. Associated probabilities and (dis)utilities to all states were derived from existing literature. Conventional TKA and RATKA differed based on the a higher outlier rate outisde of neutral mechanical alignment, possibly leading to a higher revision rate.

Results

With an acceptable threshold of 50000/QALY for cost-effectiveness, only 2.18% of cases proved to be cost-effective. At least 253 cases per robot per year need to be performed to prove cost-effective based on the model presented in this study. Utilities of primary and revision TKA had the highest impact on the Markov model.

Conclusion

Robot-assisted TKA could be a cost-effective procedure compared to conventional TKA if a minimum of 253 cases are performed on a yearly basis. The cost-benefit of the robotic TKA surgery is based on a decreased revision rate. This study is based on the assumption that alignment is a predictor of success after total knee arthroplasty. Until there is data confirming the assertion that alignment predicts success robot-assisted surgery should not be recommended.