Incorporating tissue anisotropy and heterogeneity in finite element models of trabecular bone altered predicted local stress distributions

Max A. Hammond, Joseph M. Wallace, Matthew Allen, Thomas Siegmund

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Trabecular bone is composed of organized mineralized collagen fibrils, which results in heterogeneous and anisotropic mechanical properties at the tissue level. Recently, biomechanical models computing stresses and strains in trabecular bone have indicated a significant effect of tissue heterogeneity on predicted stresses and strains. However, the effect of the tissue-level mechanical anisotropy on the trabecular bone biomechanical response is unknown. Here, a computational method was established to automatically impose physiologically relevant orientation inherent in trabecular bone tissue on a trabecular bone microscale finite element model. Spatially varying tissue-level anisotropic elastic properties were then applied according to the bone mineral density and the local tissue orientation. The model was used to test the hypothesis that anisotropy in both homogeneous and heterogeneous models alters the predicted distribution of stress invariants. Linear elastic finite element computations were performed on a 3 mm cube model isolated from a microcomputed tomography scan of human trabecular bone from the distal femur. Hydrostatic stress and von Mises equivalent stress were recorded at every element, and the distributions of these values were analyzed. Anisotropy reduced the range of hydrostatic stress in both tension and compression more strongly than the associated increase in von Mises equivalent stress. The effect of anisotropy was independent of the spatial redistribution high compressive stresses due to tissue elastic heterogeneity. Tissue anisotropy and heterogeneity are likely important mechanisms to protect bone from failure and should be included for stress analyses in trabecular bone.

Original languageEnglish (US)
Pages (from-to)1-10
Number of pages10
JournalBiomechanics and Modeling in Mechanobiology
DOIs
StateAccepted/In press - Nov 14 2017

Fingerprint

Anisotropy
Stress Distribution
Bone
Finite Element Model
Stress concentration
Tissue
Hydrostatics
Bone and Bones
X-Ray Microtomography
Elastic Tissue
Cancellous Bone
Bone Density
Femur
Collagen
Elastic Properties
Redistribution
Computational methods
Tomography
Compressive stress
Model

Keywords

  • Anisotropy
  • Collagen fiber orientation
  • Microcomputed tomography
  • Stress analysis

ASJC Scopus subject areas

  • Biotechnology
  • Modeling and Simulation
  • Mechanical Engineering

Cite this

Incorporating tissue anisotropy and heterogeneity in finite element models of trabecular bone altered predicted local stress distributions. / Hammond, Max A.; Wallace, Joseph M.; Allen, Matthew; Siegmund, Thomas.

In: Biomechanics and Modeling in Mechanobiology, 14.11.2017, p. 1-10.

Research output: Contribution to journalArticle

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