A Method for Evaluation the Fatigue Microcrack Propagation in Human Cortical Bone Using Differential X-ray Computed...

Area of Science:

• Biomechanics
• Materials Science
• Medical Imaging

Background:

• Fatigue damage in cortical bone initiates as microcracks, potentially leading to fractures.
• Understanding microcrack initiation and propagation is crucial for predicting bone failure.

Purpose of the Study:

• To investigate microcrack systems in cortical bone during simulated gait loading.
• To analyze the formation and evolution of microcracks in bone microstructure.

Main Methods:

• Time-resolved, high-resolution X-ray micro-computed tomography (micro-CT) was employed for in situ fatigue experiments.
• A laboratory micro-CT system with a loading device simulated a gait cycle (1000 cycles, 900 N peak load, 0.4 Hz).
• Projection-level and focal spot drift corrections, along with differential tomography, were used for high-quality 3D image reconstruction and microcrack identification.

Main Results:

• Microcrack initiation and propagation within the bone microstructure were observed under cyclic loading.
• The study identified crack formation and changes in microcrack topology on a volumetric basis.
• High-resolution imaging enabled visualization of microcracks comparable to Scanning Electron Microscopy (SEM) quality.

Conclusions:

• In situ X-ray micro-CT is effective for studying fatigue-induced microdamage in bone.
• The research provides insights into the early stages of bone damage development under physiological loading conditions.
• Volumetric analysis of microcracks aids in understanding bone failure mechanisms.