The Role of Synovial Fluid Properties in a Dynamic Hip Joint Simulation

Accurate mathematical modelling of joints is directly related to the need to obtain a better fundamental understanding of the role that elements of the system have on the dynamic tribological behaviour of the component it represents. Simulation models also make a contribution towards reduction of the cost of in-situ experimentation in biotribological systems, as well as overcoming difficulties with ethical and practical problems related to in-situ testing. The aim of the current work is to report on the results obtained from a dynamic model of a human hip joint. The model is used to investigate the tribological performance of the synovial fluid over a varying range of operating conditions — specifically pressure, temperature and varying load conditions. The model is based on a minimum of empirical relationships, preferring relationships grounded in solid fundamental theory. This reduces the number of parameters that can be modified in the model and ensures that predictions made are not based on external manipulations.