A knee joint prosthesis is capable of moving between an extended position and a flexion position. The knee joint prosthesis includes a femoral component that is configured to be mounted to a femur, a tibial component that is configured to be mounted to a tibia, a post fixedly connected to one of the femoral component and the tibial component, and a cam recess defined on the other of the femoral component and the tibial component that is configured to be engaged by the post in either the extended position or the flexion position of the knee joint prosthesis. The knee joint prosthesis may also include an artificial ligament that extends between the femoral component and the tibial component. The post and the ligament mimic one of the ACL and PCL.