The evaluation of fluid film lubrication in artificial knee joint with soft layer using knee joint simulator
Details
Artificial joint is generally applied for surgical operation on the patients of osteoarthritis, rheumatoid arthritis etc. Current major artificial knee joint is composed of metallic or ceramic femoral component and tibial component of Ultra high molecular polyethylene (UHMWPE), and this constitution is durable for more than 10 years in clinical use. However, it is indicated that wear debris of UHMWPE activates phagocyte or macrophage excessively, and finally the problem of loosening occurs. One of the solutions to reduce wear debris is to apply fluid film lubrication mode constructively. We observed the degree of the fluid film formation of artificial knee joint utilizing electric resistance method. In experimental processes, artificial knee joint was installed in the knee joint simulator, which could generate practical condition of walking in 4-degrees of freedom. The experimental result showed that high degree of separation by fluid lubrication occurred in the condition of tibial component of UHMWPE flat plate. Furthermore, the application of compliant material as rubbing surface improved fluid film formation in simulator test.
