Diarthrodial joint contact models: finite element model development of the human hip

The demands associated with modeling geometrically complex anatomic structures often limit the utility of musculoskeletal finite element (FE) analyses. Automated meshing routines typically rely on the use of tetrahedral elements. Hexahedral elements, however, often outperform tetrahedral elements, namely during contact analyses. Hence, a need exists for a preprocessor geared towards automated hexahedral meshing of biologic structures. Two meshing schemes for finite element mesh development of the human hip are presented: (1) a projection method, coupled with a surface smoothing algorithm, has been applied to accommodate the near spherical nature of the femoral head articular cartilage surface, while (2) a technique termed the preferential method was developed to mesh the acetabulum. The latter technique benefits from a user traced bound of the articular surface. High-quality, three-dimensional continuum models, consisting solely of hexahedral elements, were generated for the femoral head and the acetabulum. To check the validity of the meshing routines, a transient deformable–deformable contact finite element analysis was carried out. Gait cycle kinematics and kinetics from the weight-bearing stance phase were considered. The contact pressure (1.74 MPa) was in agreement with the values reported in the literature.