ConforMIS has attempted to follow a clearly different path than the major orthopaedic companies. They have chosen to offer patients a personalized knee implant based off of each patient's femoral and tibial bone geometry. The hypothesis is that these subjects will experience a more normal-like kinematic pattern, eliminating paradoxical anterior sliding during weight-bearing knee flexion. Therefore, the objective for this study is to analyze the in vivo kinematics for 25 patients implanted with a personalized ConforMIS TKA and 25 patients implanted with a traditional TKA design to determine if there are any kinematic differences between these TKA designs.