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Published on: June 12, 2020
Age-dependent fatigue behaviour of human cortical bone
1Department of Biomedical Engineering, Jonsson Engineering Center, Room 7046, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180, USA.
European Journal of Morphology
|August 27, 2005
Summary
Aging human bone shows an exponential decrease in fatigue life, with older bone exhibiting distinct stiffness loss patterns compared to younger bone. This age-related bone fragility is linked to differences in microcrack formation and damage mechanisms.
Area of Science:
- Biomedical Engineering
- Orthopedics
- Gerontology
Background:
- Bone quality is crucial for skeletal integrity, but age-related changes in bone's fatigue behavior remain poorly understood.
- Skeletal fragility increases with age, necessitating research into the underlying mechanisms of bone quality degradation.
Purpose of the Study:
- To investigate the age-dependent fatigue behavior of human bone.
- To identify damage mechanisms contributing to age-related bone fragility.
- To analyze stiffness loss and local tissue properties during fatigue loading in aging bone.
Main Methods:
- Four-point bending fatigue tests were performed on aging human bone samples.
- Stiffness loss was analyzed alongside nanoindentation measurements of local tissue stiffness.
- Histological evaluation assessed tensile and compressive damage to identify failure mechanisms.
Main Results:
- Fatigue life demonstrated an exponential decrease with increasing age.
- Older bone exhibited distinct modulus degradation profiles compared to younger bone.
- Younger bone showed diffuse damage and tensile stiffness loss, while older bone displayed linear microcracks and compressive stiffness loss.
Conclusions:
- Age-related bone fragility is significantly influenced by the propensity of older bone to form linear microcracks over diffuse damage.
- Differences in damage mechanisms and stiffness loss between young and old bone contribute to age-related skeletal fragility.
- Understanding these age-dependent fatigue behaviors is critical for developing interventions against osteoporosis and fractures.
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