Comparison of the in Vivo Stability of 2 Cementless TKA Designs

Total joint replacement is an efficacious treatment for osteoarthritis of hips and knees.Both TKA and Total Hip Artrhoplasties (THA) have excellent implant survivorship. However,patients' satisfaction is lower in TKA than THA. A possible cause of the discrepancy isthe unnatural knee kinematics after TKA. Various implants designs have been developed tosolve the problem. The most common fixation mode is cemented TKA with good survival up to15 years. However, newer series in younger patients also have shown lasting survival withcementless implants (Nilsson KG, Prudhon JL). Among various different designs, themedially stabilized total knee, which are designed to reproduce natural knee kinematicswith a medial ball‐in‐socked design, is a promising implant design (No authors listed).Dynamically the medial pivot knee performs more naturally (Bragonzoni L,Petersen ET)compared to other designs. Most data for this design is available only for the cementedversion. Up to now there is no safety study performed that confirms the stability overtime for this implant with cementless fixation.In this study, the investigators will therefore analyze the in vivo stability of anuncemented TKA with a medially stabilized design, and compare it with a well‐documentedcomparable implant. In order to do this, the investigators will use the CT basedmicromotion analysis (Broden C, Broden C). This study will contribute to theunderstanding of fixation and lead to safety to the patient.