Numerical modeling of long bone adaptation due to mechanical loading: correlation with experiments.

Area of Science:

• Biomechanical Engineering
• Computational Biology
• Orthopedic Research

Background:

• Cortical bone exhibits external adaptation in response to mechanical loading.
• Understanding bone adaptation is crucial for developing treatments for bone diseases and injuries.
• Previous studies have established the link between mechanical stimuli and bone remodeling.

Purpose of the Study:

• To develop and validate a mathematical model for external bone adaptation in cortical bone.
• To investigate the influence of mechanical stimulus parameters on bone adaptation.
• To assess the model's ability to predict experimental bone adaptation responses.

Main Methods:

• Utilized finite element (FE) stress analysis coupled with an evolution model.
• Generated FE mesh from micro-computed tomography (microCT) images of rat ulna.
• Implemented an evolution law with 'gain' and 'threshold-sensitivity' parameters to simulate adaptation.

Main Results:

• The model successfully predicted bone adaptation in rat ulna subjected to cyclic loading.
• Splitting loading cycles affected threshold-sensitivity but not the rate of adaptation.
• The threshold-sensitivity parameter quantified osteocyte mechanosensitivity.

Conclusions:

• The coupled FE and evolution model is a capable tool for predicting bone adaptation.
• Loading cycle patterns influence the mechanical threshold for bone adaptation.
• The model provides insights into the mechanobiology of bone adaptation and osteocyte function.