Finite element analysis of trabecular bone structure: a comparison of image-based meshing techniques

Area of Science:

• Biomedical Engineering
• Orthopedics
• Materials Science

Background:

• Finite element (FE) analysis is crucial for understanding bone mechanical properties.
• Micro-computed tomography (micro-CT) provides high-resolution imaging of bone architecture.
• Assessing the accuracy of FE models derived from lower-resolution bone images is essential.

Purpose of the Study:

• To evaluate the relevance of finite element (FE) analyses of human trabecular bone architecture at 168 microm resolution.
• To compare different meshing techniques for creating FE models from coarsened micro-CT data.
• To determine the impact of bone morphology on the accuracy of FE models.

Main Methods:

• Human trabecular bone samples (femoral head, iliac crest, lumbar spine) were imaged using micro-CT at 28 microm resolution.
• Image resolution was coarsened to 168 microm, and FE models were generated using hexahedral, tetrahedral, and mass-compensated hexahedral meshing.
• FE models were analyzed for elastic moduli and tissue Von Mises stresses, comparing results to a high-resolution hexahedral model.

Main Results:

• Standard hexahedral meshing at 168 microm resolution led to a loss of trabecular connections and reduced stiffness in some samples.
• Tetrahedral and mass-compensated hexahedral meshing techniques yielded more accurate results for samples with thinner trabecular bone.
• FE model accuracy at 168 microm resolution was significantly influenced by bone morphology, particularly trabecular thickness.

Conclusions:

• The accuracy of 168 microm FE models is highly dependent on bone morphology and the meshing technique employed.
• Loss of trabecular connections during hexahedral meshing at lower resolutions compromises FE analysis results.
• Tetrahedral or mass-compensated hexahedral meshing can mitigate connection loss and improve the accuracy of FE models for human trabecular bone.