Bone stiffness changes due to microdamage under different loadings

Stiffness changes due to microdamage in the longitudinal and cross-sectional directions in a dog bone model under different loadings were investigated using three-dimensional finite element analysis. Stiffness changes and severity of both longitudinal and cross-sectional type microcracks were estimated between the damaged and undamaged bone under four-point bending, torsion and tension. Finite element simulation results indicated that longitudinal damage was more severe than cross-sectional damage under axial tension and bending, and the opposite was true for torsional loading. However, for axial tension, the stiffness change due to cross-sectional microcracks remained constant.