A comparison between automatically generated linear and parabolic tetrahedra when used to mesh a human femur

Finite element models of bone segments generated from computed tomography d ata using automatic mesh generation algorithms are becoming common not only in research but also in clinical applications such as computer aided ortho paedic surgery. Especially in the case of the latter application, the model s cannot be verified against an experimental measurement, therefore their i nherent accuracy should be well known before drawing conclusions based on t he calculated results. This study was carried out to assess the performance of tetrahedral solid finite elements with linear and quadratic displacemen t functions when they are used to mesh the human femur in conjunction with automatic mesh generator methods. Ten-node quadratic tetrahedra (T10) havin g parabolic displacement functions were compared with four-node linear tetr ahedron elements (T4) on the basis of accuracy and central processing unit (CPU) time. From the analyses of 11 finite element meshes, it was concluded that linear tetrahedral elements should be avoided and quadratic tetrahedr al elements ought to be chosen for the purposes of finite element analysis of the human femur. When incremental loading and iterative solution is nece ssary, the coarsest possible T10 mesh compatible with accuracy is needed to minimize computer capacity and CPU time.