Semi-Automated μCT-Based Modeling of Vertebral Bony Endplate Microporosity and Mechanical Properties: Linking...

Area of Science:

• Biomechanics
• Spinal research
• Bone microarchitecture

Background:

• The vertebral bony endplate (BEP) is crucial for mechanical load transfer and nutrient transport to the intervertebral disc.
• BEP microstructural porosity significantly influences bone strength, elasticity, and solute diffusion, impacting spinal health.
• Variations in BEP porosity affect its mechanical competence and nutrient transport capabilities.

Purpose of the Study:

• To develop and apply a semi-automated workflow for quantifying BEP pore geometry and connectivity.
• To correlate BEP microstructural properties with zone-specific mechanical and transport characteristics.
• To assess the impact of BEP heterogeneity on its functional properties.

Main Methods:

• Micro-computed tomography was used to image 6-8 BEPs from four bovine subjects.
• A semi-automated pipeline quantified microstructural properties (tortuosity, porosity, pore radii) in central and peripheral BEP zones.
• Zone-specific density, Young's modulus, compressive strength, and shear modulus were inferred from microstructural metrics.

Main Results:

• Significant spatial, intra-subject, and inter-subject morphological variability was observed in the BEPs.
• This variability in BEP structure influenced predicted mechanical and transport properties.
• Findings underscore limitations of idealized computational models of the BEP.

Conclusions:

• Physiologically relevant variations in the BEP necessitate uncertainty modeling in in silico simulations.
• The developed semi-automated approach enhances the realism of simulations modeling vertebral endplate function.
• This methodology advances our understanding of BEP biomechanics and transport.