Tadasuke Katsuhara

A 3D model analysis for developing multifunctional knee prosthesis

Currently used knee prostheses are broadly classified into the CR type and the PS type. We are planning to develop a new type of knee prosthesis which could make a complete deep knee flexion. Although the new prosthesis should be developed on the basis of the PS rather than the CR, we should further consider about weather we could cut the PCL so readily, and weather high stress concentration might not arise on the articulation surfaces whose conformity is usually so high. Thus we performed simulation analyses subject to the CR instead of the PS, thereby introducing the relationship between the PCL function and the joint articulation conformity. Then making most of the simulation results, we designed a complete flexionable knee prosthesis designated CFK prosthesis.

Comparative study for kinetics and kinematics between the CR and PS type artificial knee joints from 3D model analyses

The objective of this study is to compare the kinetics and kinematics between the Cruciate Retaining (CR) type and the Posterior Stabilized (PS) type of the artificial knee joints from the results of a 3D mathematical model analysis of knee joint motion. Our 3D model included not only the femur-tibia joint but also the patella-femur joint can introduce variations of contact point trajectories, contact pressure on the articular surfaces. The simulation results demonstrated that, highly stable joint articulation was confirmed for the PS, yet stress concentration or disarticulations was found if the engaging or disengaging between the post and cam did not occur at an appropriate time.