Study on the Long Bone Failure Behaviors Under the Indenter Rigid-Contact by Experiment Analysis and Subject-Specific...

Area of Science:

• Biomechanics
• Materials Science
• Orthopedic Research

Background:

• Long bone bending fractures pose significant risks in sports and accidents.
• Previous studies on bone bending behavior often overlooked indenter rigidity effects.

Purpose of the Study:

• To investigate porcine long bone fracture mechanics under a rigid indenter.
• To analyze the influence of indenter rigidity on fracture dynamics and failure modes.
• To develop a subject-specific finite element model for simulating indentation effects.

Main Methods:

• Three-point bending tests on porcine long bones with a rigid indenter.
• High-speed photography to record fracture dynamics.
• Scanning electron microscopy (SEM) for mesoscale fracture surface analysis.
• CT scanning and MATLAB scripting for cross-section property calculation.
• Subject-specific finite element (FE) modeling.

Main Results:

• Indentation caused mesoscale crack-opening, leading to fracture path deflection and requiring moment correction.
• Plastic indentation resulted in force fluctuations, correlated with experimental data.
• Bone failure moment showed a stronger correlation with the inertial moment of the cross-section than the area.
• FE simulations predicted compression fractures at lower forces due to indentation; element erosion removal improved validation.

Conclusions:

• Rigid indenter effects, including crack-opening and force fluctuations, are critical in long bone bending fractures.
• The inertial moment of the bone cross-section is a more accurate predictor of failure moment than cross-sectional area.
• FE modeling with specific adjustments can effectively simulate indentation-induced bone fracture behaviors.