Femoral head apparent density distribution predicted from bone stresses

Area of Science:

• Biomechanics
• Orthopedic Research
• Material Science

Background:

• Bone morphology is influenced by applied stress.
• Cancellous bone self-optimizes, while cortical bone reaches maximum density under stress.

Purpose of the Study:

• To develop and test a new theory relating bone morphology to applied stress.
• To predict apparent density distribution in the femoral head and neck.
• To compare three different stress-based approaches for density prediction.

Main Methods:

• Modeling cancellous bone as self-optimizing and cortical bone as saturated.
• Implementing three approaches: von Mises stress, strain energy density, and closed effective stress.
• Utilizing an iterative nonlinear three-dimensional finite element model.

Main Results:

• Von Mises stress (open effective stress) failed to accurately predict bone apparent density.
• Strain energy density and closed effective stress successfully predicted apparent density.
• The predicted density patterns aligned with observed patterns in the femoral head and neck.

Conclusions:

• Strain energy density and closed effective stress are viable predictors of bone apparent density.
• The new theory provides a framework for understanding bone density distribution based on mechanical stress.
• This approach offers insights into bone adaptation and remodeling.