Factors of mineralization dynamics - A mathematical model for microstructural bone remodeling

Area of Science:

• Biomedical Engineering
• Orthopedics
• Materials Science

Background:

• Bone mineralization is vital for bone strength and fracture prevention.
• The relationship between bone porosity and mineralization is not fully understood across different bone types (cortical to trabecular).

Purpose of the Study:

• To develop a novel mathematical framework modeling bone mineralization dynamics as a function of porosity and bone turnover.
• To investigate the influence of porosity-dependent cellular activity on mineralization across the full porosity range.
• To test hypotheses explaining mineral content variations with porosity.

Main Methods:

• Developed a mathematical framework incorporating porosity-dependent cellular activity based on remodeling surface availability.
• Tested three hypotheses: variations in turnover rate, targeted resorption, and mineral apposition rate.
• Validated the model against experimental data and performed global sensitivity analysis.

Main Results:

• Successfully reproduced the relationship between material and apparent density across varying bone porosities.
• Identified porosity-dependent turnover and mineral apposition rate as primary drivers of mineralization.
• Mineral apposition rate was confirmed as the most influential parameter.

Conclusions:

• The novel framework provides a mechanistic explanation for bone mineralization variations across the porosity spectrum.
• Trabecular microarchitectural variations contribute to data dispersion in mid-porosity ranges.
• The model enhances understanding of bone quality and fracture risk.