Femur mechanical simulation using higher-order finite-element
analysis with continuous mechanical properties

R. Fedida (1), Z. Yosibach (1), C. Milgrom (2), and L. Joskowicz (3)

Abstract:

Femur 3D finite-element (FE) analysis based on CT data requires both
accurate geometry representation and mechanical properties assignment. A
"structure based" method is suggested for the reconstruction of a FE model
so that the geometry is represented by smooth surfaces extracted from the
CT data including a separating surface between cortical and trabecular
regions. Then, p-FE automesh is generated. Within each region (cortical or
trabecular), the heterogeneous density is described by continuous spatial
functions that are generated using Least Squares Minimum (LST)
approximations based on the Ct data scan. Finally, the Young modulusi9s
evaluated continuously according to teh functional representation of the
density. Numerical investigation shows good results of the suggested method
compared to the voxel-based method. Mechanical in-vitro experiments on
fresh frozen femur measuring head deflection and strains at several points
is currently used for FE model calibration and validation.

Keywords: FEA, femur  modeling, stress analysis

Published in: Proc. 2nd Int. Conf. on Computational Bioengineering, Lisbon,
Portugal.  Rodrigues H. et al. editors, IST press, Volume 1, pp.85-96,
September 2005.