Histomorphometric Differences in Tibial Cortical Bone Based on Sampling Location

Abstract

Histomorphometric analysis of cortical bone is often used to estimate age at death of skeletons or to make inferences about mobility in past populations. Although previous studies have indicated that remodeling is variable within a single cross-section of bone, there has been little examination of the nature of these differences in the human tibia. This study investigated whether there are differences in remodeling based on sampling location in human tibiae, specifically examining inter-quadrant differences (anterior, posterior, medial, and lateral) as well as differences between periosteal, endosteal, and midcortical sampling locations. Slides of undecalcified sections of human tibiae at midshaft (N=10) were used to analyze histomorphometric properties including percent remodeled bone, osteon population density (OPD), Haversian canal size, and osteon size. Results indicate that there is a difference in remodeling of the cortical bone that is dependent on sampling location. Remodeling parameters differ between anatomical quadrants, with the anterior quadrant typically exhibiting higher rates of remodeling. Midcortical sampling locations exhibited greater remodeling than either endosteal or periosteal regions. Furthermore, the selection of magnification level and field size can significantly affect the measurement of OPD. These results support the idea that remodeling can progress in contrasting ways between various areas of the same cross- section of bone. Therefore, care should be taken when comparing histomorphometric properties from different areas of tibial cortical bone.