Static and Dynamic Analysis of a Prosthetic Human Knee

The first objective of this paper is to study the influence of a prosthesis on the maximum values of contact stresses developed in the components of the virtual model of a prosthetic knee assembly, using Finite element analysis (FEA). The second objective is to estimate Lyapunov exponents (LEs) in order to quantify the local dynamic stability of the human knee joint during walking overground for healthy subjects and for patients suffering of osteoarthritic knee (OAK), before and after total knee replacement (TKR), using tools of dynamics stability analysis. The values of the LEs are obtained based on the experimental time series of the flexion-extension movements in sagittal plane and the rotational movements in frontal plane for both knees, collected from a sample of healthy subjects and a sample of patients suffering by OAK before and after TKR. The influence of prosthesis mounted in OAK is positive, the values of LEs obtained for OAK four month after TKR are associated with increased stability, being smaller than those computed for OAK before TKR, and closer than those obtained for healthy knees.