Applications of an anisotropic parameter to cortical bone

Area of Science:

• Biomechanics
• Materials Science
• Orthopedics

Background:

• Cortical bone exhibits anisotropy, a complex property.
• Existing methods for describing anisotropy are limited.
• Understanding bone's mechanical properties is crucial for skeletal research.

Purpose of the Study:

• To present an equational description of cortical bone anisotropy.
• To refine the understanding of planar and volumetric anisotropy.
• To introduce new parametric equations for anisotropy analysis.

Main Methods:

• Utilized plane stress and plane strain models.
• Incorporated orthotropic elastic properties.
• Applied anisotropic parametric equations (eta(sigma) and eta(epsilon)) to existing data.

Main Results:

• Reduced nine independent properties to three parameters.
• Found no significant difference between plane stress and plane strain parameters in most cases.
• Confirmed volumetric anisotropy in all studied cortical bone samples.
• Identified a common plane of isotropy in the radial-circumferential direction.

Conclusions:

• The new parametric equations provide a refined description of bone anisotropy.
• Cortical bone is consistently volumetrically anisotropic.
• The radial-circumferential plane often exhibits isotropy.
• These equations can aid in analyzing anisotropy in other biological tissues and materials.