Cost-effectiveness model comparing dual-mobility to fixed-bearing designs for total hip replacement in France

BackgroundInstability is among the main causes of total hip arthroplasty (THA) failure. In clinical studies, THA with a dual-mobility cup (THA-DM) decreased the risk of instability after primary THA compared to THA with a fixed-bearing design (THA-FB). However, whether THA-DM is more cost-effective than THA-FB has not been established using Markov modelling with determination of the incremental cost-effectiveness ratio (ICER). The objectives of this work were to: (1) measure the efficiency of these two options, (2) use the nationwide hospital electronic database (PMSI) to estimate direct costs of dislocations and revisions for instability, and (3) conduct deterministic and probabilistic sensitivity analyses to estimate potential mean annual cost-savings in France.HypothesisWe hypothesised that primary THA-DM was cost-saving compared to primary THA-FB.Material and methodsIn the database, we identified 80,405 patients who had THA in 2009 and we collected their outcomes over 4 years (2009–2012). Cost-effectiveness was assessed based on the costs of resources used for all consequences of prosthetic dislocation and paid for by the statutory health insurance system or other sources.ResultsTHA-DM was associated with a relative risk of dislocation of 0.4 versus THA-FB. This risk difference translated into 3283 fewer dislocations per 100,000 patients with THA-DM. The corresponding cost-savings for the 140,000 primary THA procedures done in France annually was 39.62 million Euros. A relative risk of 0.2 would yield annual cost-savings of 56.28 million Euros. In the probabilistic sensitivity analysis, THA-DM was the less costly option under all hypotheses, with potential maximum cost-savings of more than 100 million Euros per year in France.DiscussionThis comparative cost-effectiveness analysis suggests that THA-DM may induce substantial cost-savings compared to THA-FB. This possibility should be assessed by long-term clinical studies of new-generation DM prostheses.