Micromechanical modelling of cortical bone

Abstract

Cortical bone is a heterogeneous material with a complex hierarchical microstructure. In this work, unit cell finite element models were developed to investigate the effect of microstructural morphology on the macroscopic properties of cortical bone. The effect of lacunar and vascular porosities, percentage of osteonal bone and orientation of the Haversian system on the macroscopic elastic moduli and Poisson's ratios was investigated. The results presented provide relationships for applying more locally accurate material properties to larger scale and whole bone models of varying porosity. Analysis of the effect of the orientation of the Haversian system showed that its effects should not be neglected in larger scale models. This study also provides insight into how microstructural features effect local distributions and cause a strain magnification effect. Limitations in applying the unit cell methodology approach to bone are also discussed.

A three-scale finite element investigation into the effects of tissue mineralisation and lamellar organisation in human cortical and trabecular bone

“…Also, both osteons and trabeculae exhibit a certain level of porosity due to the presence of lacunar and canalicular cavities which have not been included in the current models. However, Mullins et al (2007) showed that while lacunar cavities (accounting for 3% porosity) could cause a local strain amplification of up to seven times the applied global strain, their effect on the homogenised mechanical properties was less than 5%. As the focus of this analysis was to determine homogenised stiffness values for the tissue level, these simplifications were deemed acceptable in order to efficiently apply a periodic homogenisation approach to the microstructural models.…”

Cortical bone failure mechanisms during screw pullout

“…However, in the present study we highlight the deficiency of homogeneous modelling of cortical bone for screw pullout. An inhomogeneous computational unit cell model highlights the necessity of accounting for material orientation in large scale models as the effects are not negligible (Mullins et al, 2007). Use of XFEM has been reported for 2D models of cortical bone incorporating a representation of the microstructure of cortical bone.…”

Alterations of Mass Density and 3D Osteocyte Lacunar Properties in Bisphosphonate-Related Osteonecrotic Human Jaw Bone, a Synchrotron µCT Study

“…The morphology of the lacuno-canalicular network (LCN) is believed to be related to the mechanosensation and mechanotransduction processes of osteocytes [21]–[31]. Furthermore, the LCN ensures the transport of cellular waste and nutrients [23].…”