Associate Professor, Department of Science of Materials of the University of Cantabria, Spain

Speech Title: Does the orientation of the bone matter during bending test?
Abstract: The influence of the orientation of rat bones on their mechanical response is analyzed in this research. 28 femora obtained from 14 Sprague-Dawley rats were subjected to three-point bending tests, comparing the anteroposterior and posteroanterior orientations. The results show that the whole-bone loading capacity of the femora tested in the posteroanterior orientation clearly exceeds that of the anteroposterior oriented bones. Likewise, the intrinsic (tissue-level) loading capacity of the bones tested in the posteroanterior orientation is manifestly higher than that of the bones tested in the opposite direction. The analysis carried out shows that applying beam theory for symmetric cross-sections leads to underestimating the stress state in the cross-section. It was found out that it is the variation in the intrinsic properties, which explains the change measured in the whole-bone properties. The experimental scope was increased, including 8 additional femora on which a series of Vickers tests were carried out in the anterior and posterior regions of the cross-section. In all cases, the hardness obtained in the anterior region is larger than in the posterior region. This result confirms that the mechanical properties of the bone tissue are depend on its position in the cross-section and provides a reliable explanation to understand the response of the bones when subjected to bending tests.