Bone morphology and mechanical Behavior: New insights into cortical and trabecular failure under compression

Area of Science:

• Biomechanics
• Biomaterials Science
• Skeletal Biology

Background:

• Bone is a complex tissue with distinct cortical and trabecular structures.
• Understanding the microscale relationship between bone structure and mechanical properties is crucial.
• Current knowledge of how microstructure influences whole-bone mechanics is incomplete.

Purpose of the Study:

• To identify key morphometric characteristics of cortical and trabecular bone.
• To investigate the relationship between these characteristics and mechanical behavior.
• To understand failure mechanisms in bone under loading.

Main Methods:

• Mechanical compression testing on pig rib bone slices.
• Digital Image Correlation (DIC) for tracking local displacements and failure.
• Micro-computed tomography (micro-CT) and Dragonfly software for morphometric analysis.

Main Results:

• Bone parameters, especially total bone mass and cortical morphology, significantly impact mechanical properties like stiffness and strength.
• Fractures primarily initiate in areas of lower density and less organized trabecular bone.
• Elastic properties and post-collapse strength are strongly correlated with bone morphology.

Conclusions:

• Cortical bone morphology and overall bone mass are critical determinants of mechanical performance.
• Trabecular bone's structural integrity, specifically its density and organization, dictates fracture initiation sites.
• This study enhances the understanding of bone's micro-to-macro mechanical behavior and failure modes.