Uniform stress state in bone structure with residual stress

Area of Science:

• Biomechanics
• Biomaterials Science
• Skeletal Biology

Background:

• Living tissues maintain mechanical optimality through adaptive remodeling.
• Residual stresses and strains are crucial for understanding tissue mechanics.
• Bone's complex structure influences its mechanical properties.

Purpose of the Study:

• To investigate residual stresses in the cortical-cancellous bone complex of bovine coccygeal vertebrae.
• To analyze the distribution of residual stress in different bone compartments and directions.
• To evaluate the mechanical optimality hypothesis in bone structures.

Main Methods:

• Biaxial strain gauges were attached to the cortical surface of bovine vertebrae.
• Strain measurements were recorded after sequential removal of the end-plate and cancellous bone.
• Mechanical models (three-bar and three-layered cylinder) were used to analyze observed strains.

Main Results:

• Compressive residual stress was found in cortical bone.
• Tensile residual stress was observed in cancellous bone.
• Effective stress magnitudes were similar in cephalocaudal and circumferential directions, supporting the uniform stress hypothesis.

Conclusions:

• The study demonstrates a significant role of residual stress in the mechanical behavior of bone.
• The findings are consistent with the uniform stress hypothesis when residual stresses are accounted for.
• This research contributes to understanding the adaptive remodeling and mechanical optimality of bone tissue.