For the CNEDiMTS re-evaluation of the Service Provided by Hyaluronic Acids, RCTs initiated a joint reflection with the manufacturers to provide elements in favour of the medico-economic interest of hyaluronic acids in the management of gonarthrosis in France. The Markov model built in collaboration with an independent scientific committee accounts for a therapeutic care over a “lifetime” horizon in fictitious cohort of patients suffering from knee osteoarthritis, in order to estimate a differential cost-result ratio (ICER ).