Bone quality in prehistoric, cis‐baikal forager femora: A micro‐CT analysis of cortical canal microstructure

Abstract

Bone quality, a contributor to bone strength, is determined by structural and mechanical properties, which may be analyzed by gross and/or microscopic methods. Variables that contribute to bone quality, such as porosity, can provide insight into the health and lifestyles of people in prehistory. This study tests the ability of microcomputed tomography (µCT) to capture and characterize cortical canal systems in archaeological bone. Seven variables and 71 femora are analyzed to explore bone dynamics in prehistoric foragers from Lake Baikal, Siberia. The results indicate that canal number and canal separation differ significantly (P < 0.05) between age-at-death categories, but only for the pooled and male samples. When merged into a new variable by means of principal components analysis, canal diameter and canal surface to canal volume are also able to discriminate amongst age-at-death categories, as well as between the sexes. However, the overall lack of significant differences between the sexes and amongst age-at-death categories indicates that Baikal forager bone quality (i.e., canal architecture) did not change drastically throughout the lifespan. Interestingly, principal component one identified an untested variable that contributes to canal microstructure variability, and a sexual division of labor may promote divergent trends in canal degree of anisotropy between the sexes. Overall, µCT provides an alternate method for exploring bone quality in archaeological remains, complementing existing methods such as thin-sectioning and gross morphological analyses.

Functional morphology in the pages of the AJPA

“…Although cortical bone microstructure provides much information on the dynamics of bone growth and remodeling, with potential functional implications (e.g., see Martin, Burr, & Sharkey, ), it has been relatively less studied in comparative anthropological contexts. This is in part because of the necessity for physical sections, although recent improvements in very high‐resolution computed tomography may make noninvasive assessments of at least some parameters more feasible in the future (Faccia et al, ). A histomorphometric study of cortical bone in 10 late archaic and early anatomically modern Homo sapiens lower limb specimens, published in the AJPA (Abbott, Trinkaus, & Burr, ), concluded that osteon size and remodeling rates were lower than those of more recent humans, which was interpreted as reflecting higher mechanical loads (following the “Mechanostat” model proposed by Frost, ).…”