Tribological Modeling Of The Hip Joint

The paper presents a series of aspects regarding the main biotribological phenomena occurring in the synovial joints. Although a great deal of research is carried out around the world about the biotribological processes in the human body's synovial joints, due to their complexity, they are not yet been fully understood and cannot establish a unique model of lubrication mechanism in these joints. The problem is complicated by the fact that in reality the cartilage is neither homogeneous nor isotropic and undergoes a large deformation during loading. According to several researchers, implantation and expulsion of synovial fluid in cartilage is not a simple phenomenon, although the boosted or weeping type of lubrication suggests this. The self-generating lubrication mechanism postulated by Mow et al. (1987) takes into account the biphasic nature of cartilage and is based on the load-dividing factor between the solid phase and the liquid. In recent years, studies have also been carried out to explore possible links between synovial joint lubrication mechanisms and degeneration processes. Tribological modeling is based on a number of parameters, such as: lubricant film thickness (or synovial fluid), maximum physiological load, articular cartilage surface roughness, friction coefficient, surface roughness, and lubrication regime.