Development of a 9 Axes Machine Tool for Bone Cutting

The femur and the tibia must be shaped to ensure that they are fit firmly to an artificial joint in total knee joint replacement The normal procedure is to manually cut the bones using a bone saw and mechanical jigs. A 9 axes bone cutting machine tool has been developed by the authors to increase cutting accuracy and reduce the hospital stay required for recuperation. As developed, the cut plane is determined by a 5 degree-of-freedom mechanism and the femur and tibia are cut by moving two translational and one rotational degrees of freedom to avoid the ligament. Preoperative planning system as a CAD/CAM system and overview of the assisting system for total knee arthroplasty are also discussed. Experimental results for bone cutting are presented.