Assessment of the directional elastic moduli of ewe vertebral cancellous bone by vibrational testing

The ovariectomized ewe is being used as an animal model for postmenopausal osteoporosis. Data on the mechanical properties of ewe vertebral cancellous bone is needed to assess its effectiveness as a model for vertebral osteop orosis. This study utilized traditional compression testing and a novel non destructive vibrational testing method to assess the directional mechanical properties of ewe vertebral cancellous bone. Composition and density prope rties were also assessed. It was hypothesized that vibrational testing woul d have utility in that it would allow for the anisotropic stiffness of canc ellous bone to be assessed nondestructively. The present study has found th at ewe vertebral cancellous bone has similar physical and mechanical proper ties to humans. The vibrational testing method described was able to nondes tructively provide a valid measure of stiffness that was correlated with st iffness estimates from traditional compression testing. Furthermore, the st iffness measure from the vibration test was found to be sensitive to the ar chitecture of cancellous bone. These results suggest the promise of this re sting method for the nondestructive mechanical assessment of skeletal tissu e. (C) 1999 Biomedical Engineering Society. [S0090-6964(99)00402-6].