Fast and accurate specimen-specific simulation of trabecular bone elastic modulus using novel beam-shell finite...

Area of Science:

• Biomechanics
• Materials Science
• Medical Imaging

Background:

• Trabecular bone properties are crucial for skeletal health and are diminished by diseases like osteoporosis.
• Micro-computed tomography (micro-CT) based beam models offer efficient bone competence assessment but struggle with plate-like structures.
• Existing models lack accuracy for trabecular bone with a high proportion of plate-like trabeculae.

Purpose of the Study:

• To enhance micro-CT based bone modeling by accurately representing plate-like trabeculae to improve mechanical behavior prediction.
• To develop a novel beam-shell modeling approach for trabecular bone analysis.

Main Methods:

• An optimized skeletonization and meshing algorithm was employed to simplify voxel-based trabecular bone models.
• Rod-like trabeculae were modeled as beam elements and plate-like trabeculae as shell elements, incorporating local histomorphometric data.
• Apparent elastic modulus was calculated using the novel beam-shell models and compared against gold-standard large-scale voxel models.

Main Results:

• The beam-shell models demonstrated excellent agreement (R²=0.97) with large-scale voxel models in predicting apparent elastic modulus.
• A significant average CPU-time reduction factor of 49 was achieved with the beam-shell models compared to voxel models.
• The beam-shell models accurately predicted elastic modulus across various skeletal sites, outperforming previous skeleton-based beam models.

Conclusions:

• The developed beam-shell model accurately captures the mechanical behavior of trabecular bone, including plate-like structures.
• This methodology offers a computationally efficient and accurate approach for analyzing bone competence.
• The model facilitates detailed parametric analyses across the full spectrum of trabecular bone microstructures.