An Investigation on the Mechanical Competence of the Trabecular Bone

Abstract

Osteoporosis is a disease that has become quite important nowadays due to the longer life expectancy of the population worldwide. It is mainly characterized by bone mass loss and trabecular structure deterioration, which lead to an increase in bone fragility. The bone mass loss is assessed based on measurements of bone mineral density, performed using appropriate densitometry. However, it has been known that the densitometry alone is not able to estimate the risk of fracture of a subject. Another important aspect is the trabecular bone microarchitecture, which can be investigated by image-based examinations, that normally provide 2D or 3D set of images. Some structural parameters have been investigated to describe the mechanical competence of the trabecular bone. In this paper we investigate the relationship between some of these parameters, namely: the trabecular bone connectivity, using the Euler-Poincaré Characteristic (EPC), the trabecular volume fraction (BV/TV) and the Young’s Modulus (YM). For that, three distinct set of vertebrae of different subjects, based on their tomographic images were analyzed. The YM has been obtained by simulation using finite element method (FEM) based on grayscale intensity. The results seem consistent and can be grouped according to two distinct aspects: one group has high YM with EPC predominantly negative, suggesting a good trabecular connectivity, and a BV/TV above 50% ; the other group has a low YM, with EPC predominantly positive, suggesting a low trabecular connectivity, and a BV/TV less than 50% . The analysis of multiple correlation among BV/TV, EPC and YM have shown a strong positive correlation between BV/TV and YM, and a negative one between EPC and YM, and between EPC and BV/TV. In addition, the principal component analysis confirmed the results.