The purpose of this experimental study is to present the design and biomechanical characteristics of mobile bearing postero-stabilised total knee prosthesis type MC2�- C2F� and to evaluate their use in severe primary knee osteoarthritis. The experimental part was carried out on 20 patients who benefited from mobile bearing postero-stabilised total knee prosthesis type MC2� in University Hospital Sf Spiridon Iasi, Romania. From the radiological point of view there were no mechanical complications in a 3 year follow-up. The functional recovery had a good outcome and patients currently have an active flexion between 70� and 110�, with extension between 0� and -15�. No pain was registered in full weight bearing and in active joint movement.The clinical and radiological outcome at 3 year follow-up is satisfactory and the results convinced the authors that this type of prosthesis is a good option in any primary knee osteoarthritis with no significant bone loss.