THE RELATIONSHIP BETWEEN THE STRUCTURAL AND ORTHOGONAL COMPRESSIVE PROPERTIES OF TRABECULAR BONE

In this study, cubes of trabecular bone with a wide range of structura l properties were scanned on a micro-computed tomography system to pro duce complete three-dimensional digitizations from which morphological and architectural parameters could be measured in a nondestructive ma nner. The cubes were then mechanically tested in uniaxial compression in three orthogonal directions and to failure in one direction to find the orthogonal tangent elastic moduli and ultimate strengths. After t esting, the cubes were weighed and ashed to determine the apparent and ash densities. A high correlation between the basic stereologic measu rements was found, indicating that there is a relationship between the amount of bone and number of trabeculae in cancellous bone. Regressio n analysis was used to estimate the modulus and ultimate strength; the se regressions accounted for 68 90% of the variance in these measures. These relationships were dependent on the metaphyseal type and donor, with the modulus also dependent on the direction of testing. This ind icates that the properties of the individual trabeculae, as well as th eir amount and organization, may be important in predicting the mechan ical properties of cancellous bone.