Development and experimental validation of a dynamic numerical model for human articular cartilage

Area of Science:

• Biomechanics
• Biomaterials Science
• Computational Mechanics

Background:

• Existing models for articular cartilage (AC) often simplify loading conditions to static, with limited experimental validation.
• Accurate prediction of AC's dynamic mechanical behavior under physiological loading is crucial for understanding joint health and disease.

Purpose of the Study:

• To develop and experimentally validate Finite Element Analysis (FEA) models for predicting the dynamic mechanical behavior of human articular cartilage (AC).
• To compare the predictive accuracy of linear elastic, Neo-Hookean, and Ogden hyperelastic models against experimental data.

Main Methods:

• Construction of three distinct FEA models for human articular cartilage: linear elastic, Neo-Hookean, and third-order Ogden hyperelastic.
• Validation of models using compression testing data from human femoral heads, encompassing quasi-static and dynamic mechanical analysis (DMA) up to 1.7 MPa.

Main Results:

• The linear elastic model significantly overpredicted displacement dynamic amplitude (10-fold).
• The Neo-Hookean model accurately predicted dynamic amplitude but overestimated initial compression (10-fold).
• The third-order Ogden model demonstrated the best performance, with initial compression within one standard deviation and dynamic amplitude of the same order of magnitude as experimental data.

Conclusions:

• The third-order Ogden hyperelastic model provides the most accurate representation of human articular cartilage's fast dynamic response among the tested models.
• Experimental validation is essential for refining FEA models of biological tissues like articular cartilage.