Large-scale finite element analysis of human cancellous bone tissue micro computer tomography data: a convergence...

Area of Science:

• Biomechanics
• Materials Science
• Medical Imaging

Background:

• Finite element (FE) modeling of complex cancellous bone geometry presents challenges.
• Previous studies on Cartesian mesh convergence at the tissue scale lack ideal patch tests and postelastic analysis.
• Microfinite element (microFE) models are crucial for understanding bone tissue biomechanics.

Purpose of the Study:

• To investigate the convergence behavior of microFE models of human cancellous bone at the tissue scale.
• To compare convergence of displacement, third principal strain, and stress using linear-elastic and nonlinear constitutive equations.
• To establish reference parameters for future biomechanical studies.

Main Methods:

• Generated human microFE models of cancellous bone at varying resolutions, with 19.5 μm as the reference.
• Performed uni-axial compression simulations using linear-elastic and nonlinear constitutive equations.
• Compared results (displacement, third principal strain, and stress) against the reference model.

Main Results:

• Percentage differences in all investigated parameters decreased as element size decreased.
• Displacement showed the fastest convergence rate among the three parameters.
• Nonlinear simulations failed to achieve convergence for third principal strains and stresses.

Conclusions:

• Cartesian meshes for human cancellous bone achieve converged solutions for linear simulations (displacement, strain, stress).
• Nonlinear simulations only show convergence for displacement at the tissue level.
• Further research is needed to understand convergence in nonlinear simulations for cancellous bone biomechanics.