Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (µCT)

ABSTRACT

INTRODUCTION: Trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. METHODS: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freezed at - 20 °C before carrying out the microCT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). RESULTS: The Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transverserly isotropic symmetry. DISCUSSION: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (∝CT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases.