SUMMARY

Trabecular bone microdamage has significant implications in the normal maintenance of bone structure as well as in aging situations where an accumulation of unrepaired microdamage may lead to fractures in the hip, spine, or wrist. In order to assess the significance of microdamage in skeletal fragility and traumatic fractures, the local mechanisms of bone failure must be elucidated. A better understanding of this local mechanical environment is also important to the improvement of fracture risk assessment and the development of therapies for bone fragility diseases such as osteoporosis. The overall objective of this research project was to quantitatively assess trabecular level stresses and strains associated with the initiation of microdamage. To elucidate the mechanisms of bone microdamage, this research project developed a specimen-specific approach that integrated 3D imaging, histological damage labeling, image registration, and image-based finite element analysis to correlate microdamage initiation events with local stresses and strains under compressive loading conditions. By applying this technique to different ages of human and bovine trabecular bone, this research study has provided an improved understanding of the relationship between the local mechanical environment and microdamage. The proposed research is significant because it will improve our understanding of trabecular bone microdamage initiation and may provide a measure of bone quality that may contribute to the development of skeletal fragility therapies.