Age-related changes in the 3 D hierarchical structure of rat tibia cortical bone 2 characterized by high resolution micro-CT 3 (original) (raw)

Three-dimensional hierarchical structure of female Sprague-Dawley rat tibia cortical 11 bone was characterized as a function of age (3, 12, 32, 42, 60, and 72 weeks) using a high 12 resolution micro-computed tomography. At the whole bone level, 3 week samples exhibited 13 statistically significant differences in a mean total tissue volume, mean cortical bone volume, 14 mean cortical bone volume density, mean periosteal perimeter, and mean cortical thickness (p < 15 0.05) compared to all other ages. At the tissue level, there was a statistically significant increase 16 in a mean canal number density and a decrease in a mean canal volume and diameter between 3 17 week and 12 week samples. While no significant variations were found between mean canal 18 lengths, there was a dependence of mean canal orientation on age. At the cell level, there were no 19 statistically significant differences in a lacuna number density and a lacuna volume density, and 20 all lacunae element-based para...