RESUMO
This paper presents the development of a detailed articulating three-dimensional finite-element model of the human knee, derived from MRI scan images. The model utilises precise material models and many contact interfaces in order to produce a realistic kinematic response. The behaviour of the model was examined within two fields of biomechanical simulations: general life and car-crash. These simulations were performed with the non-linear explicit dynamic code PAM-SAFE trade mark. The knee model produced results that compared favourably with existing literature. Such a model (together with other joint models that could be constructed using the same techniques) would be a valuable tool for examining new designs of prosthesis and mechanisms of injury.
Assuntos
Simulação por Computador , Imageamento Tridimensional/métodos , Traumatismos do Joelho/diagnóstico , Traumatismos do Joelho/fisiopatologia , Modelos Biológicos , Acidentes de Trânsito , Atividades Cotidianas , Cadáver , Marcha/fisiologia , Humanos , Articulação do Joelho/patologia , Articulação do Joelho/fisiopatologia , Ligamentos Articulares/patologia , Ligamentos Articulares/fisiologia , Imageamento por Ressonância Magnética , Meniscos Tibiais/patologia , Meniscos Tibiais/fisiopatologia , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estresse MecânicoRESUMO
The stress distribution within the polyethylene insert of a total knee joint replacement is dependent on the kinematics, which in turn are dependent on the design of the articulating surfaces, the relative position of the components and the tension of the surrounding soft tissues. Implicit finite element analysis techniques have been used previously to examine the polyethylene stresses. However, these have essentially been static analyses and hence ignored the influence of the kinematics. The aim of this work was to use an explicit finite element approach to simulate both the kinematics and the internal stresses within a single analysis. A simulation of a total knee joint replacement subjected to a single gait cycle within a knee wear simulator was performed and the results were compared with experimental data.The predicted kinematics were in close agreement with the experimental data. Various solution-dependent parameters were found to have little influence on the predicted kinematics. The predicted stresses were found to be dependent on the mesh density. This study has shown that an explicit finite element approach is capable of predicting the kinematics and the stresses within a single analysis at relatively low computational cost.
