Department of Anthropology, University of Toronto
Friday All day, Clinch Concourse
The biological function of drifting osteons remains obscure and has been attributed to possible mechanical, metabolic or ontogenetic purposes. Capturing the spatial orientation and geometric attributes of drifting osteons may yield further insight to their biological significance. The use of geographic information systems (GIS) to analyze the spatial distribution of histomorphological features in human bone has recently been established as a promising direction in bone histology which offers a robust and flexible approach to examining the physiological function of periosteal, intracortical, and endosteal envelopes, and their respective bone microstructure. This study uses GIS software to identify and evaluate the spatial occurrence of drifting osteons in the cortical bone envelope with respect to age-at-death and sex.
Cross-sections from a sample of 90 mid-thoracic rib midshafts from modern cadaveric populations with known age-at-death were imaged using transmitted light at 100x magnification to create complete cross-sectional montages for each sample. Cross-sectional montages were individually imported into QGIS, and observations of intact and fragmented osteon were performed and manually annotated as point data. The periosteal contour, endosteal contour, intact osteons and their Haversian canals were manually traced as polygon data. A drift index was created from a minimum bounding rectangle, centroid and Haversian canal location to identify drifting osteons. A positive spatial autocorrelation for directionally drifting osteon can be identified in most cases. GIS-based method holds great promise for future research in bone histology.