Femoral Component

Since femoral components have a sliding surface with polyethylene, the material has (1) high stability in vivo (bioinert), resistance to corrosion (high corrosion resistance), low toxicity (biocompatibility), (2) high hardness (wear resistance), (3) high fatigue strength against repetitive stress (toughness), (4) hard and nondeformable, (5) resistant to impact, (6) light as much as possible, and (7) easy to process and form. These properties have a direct impact on the durability of femoral components, the wear of polyethylene and the occurrence of metal allergies. Materials with high hardness are advantageous as sliding surface materials for artificial joints because the surface can be finished extremely smoothly (mirror surface) by polishing. Further, materials with high hardness have good wear resistance against third bodies. For example, cobalt-chromium alloy is a hard alloy and is often used as a material for femoral components, but surface properties of the retrieved components are coarser than those of ceramic components, and it is known that the amount of polyethylene wear increases when simulator tests are performed using retrieved components made from cobalt-chromium alloy compared to new ones [1, 2]. In addition, adhesion property of the material to bone cement in the case of cement fixation and initial fixation ability and affinity (promotion of bone ingrowth) for bone in the case of cementless fixation can affect the clinical results.