Micromechanical Analyses of Individual Trabeculae in µCT Based Nonlinear Finite Element Models of Human Vertebral Trabecular Bone

(Collaborative Project with Berkeley Orthopaedic Biomechanics Laboratory, UC Berkeley)

With aging, the strength of vertebral bones is impaired by the trabecular bone loss and trabecular network disruption. It has been observed that the replacement of plate-like trabeculae with the rod-like trabeculae leads to increased bone fragility. Moreover, the reduced horizontal struts have been suggested to further reduce the buckling strength of vertical trabeculae. However, there are no available quantitative data on the contribution of plate-like trabeculae vs. rod-like trabeculae.

With aging, the strength of vertebral bones is impaired by the trabecular bone loss and trabecular network disruption. It has been observed that the replacement of plate-like trabeculae with the rod-like trabeculae leads to increased bone fragility. Moreover, the reduced horizontal struts have been suggested to further reduce the buckling strength of vertical trabeculae. However, there are no available quantitative data on the contribution of plate-like trabeculae vs. rod-like trabeculae.

In addition, the loss of horizontal trabeculae in aging vertebral trabecular bone has led to the controversy regarding the relative contribution of horizontal and longitudinal trabeculae in the strength of vertebral trabecular bone. To quantitatively characterize the micromechanics of trabecular bone failure at the individual trabeculae level will improve our understanding of the etiology of age-related vertebral fractures and identify the important microstructural features such as trabecular plates or horizontal trabecular rods in determining mechanical integrity of vertebral trabecular bone, in addition to bone volume fraction.

We have developed a new segmentation technique of individual trabecular plates/rods, in conjunction with materially and geometrically nonlinear micro-computed tomography (µCT) based finite element analysis, which allows explicit determination of micromechanics of individual trabecula failure. The aim of the current study is to determine the role of (1) trabecular types (plates vs. rods) and (2) trabecular orientation (horizontal vs. longitudinal/oblique) in the initiation and progression of plastic yielding in vertebral trabecular bone. This represents a first quantitative study of micromechanics of human vertebral trabecular bone at the individual trabecula level.

Related Publications

  1. Liu XS, Gupta A, Bevill G, Keaveny KM, Guo XE, Micromechanical Analysis of Individual Trabeculae in a µCT Based Nonlinear Finite Element Model of Human Vertebral Trabecular Bone, Chicago, Illinois, March 19-22, 2006
     
  2. Liu XS, Gupta A, Bevill G, Keaveny KM, Guo XE, Micromechanical Analysis of Human Vertebral Trabecular Bone At Individual Trabecula Level, ASME Summer Bioengineering Conference , Amelia island, FL, June 21-25, 2006