The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)


Ontogenetic development of trabecular bone in the human postcranial skeleton

TIMOTHY M. RYAN1,2, SIMONE SUKHDEO1, BERNADETTE PERCHALSKI1, ZACHARIAH R. HUBBELL3, DAVID A. RAICHLEN4 and JAMES H. GOSMAN3.

1Department of Anthropology, Pennsylvania State University, 2Center for Quantitative X-Ray Imaging, Pennsylvania State University, 3Department of Anthropology, Ohio State University, 4School of Anthropology, University of Arizona

March 26, 2015 2:15, Grand Ballroom E/F/G Add to calendar

The onset and continued maturation of bipedal walking in humans is associated with significant increases in body mass and mechanical loading of the postcranial skeleton. This study investigates the role of these locomotor and mechanical changes on the developing trabecular bone structure in a suite of five long bone metaphyseal locations. We predict that the ontogenetic patterns of trabecular bone structure will reflect general developmental processes influenced by site-specific joint kinematics and kinetics. Three-dimensional trabecular bone architecture in the proximal humerus, proximal and distal femur, and proximal and distal tibia was quantified from microCT data in 71 individuals from the Norris Farms #36 archaeological skeletal collection. Individuals ranged in age from neonate to adult. Results indicate that metaphyseal trabecular bone follows very similar patterns of development in most of these long bone sites. Bone volume fraction (BV/TV) is highly variable within and between individuals, remaining relatively constant throughout ontogeny. Connectivity density (Conn.D) decreases significantly with increasing age, while both trabecular thickness (Tb.Th) and spacing (Tb.Sp) both increase significantly until adulthood. The degree of anisotropy displays the highest variation between sites, possibly reflecting local functional adaptation to joint-specific loading. The proximal femur stands out in having significantly higher BV/TV with thicker and less widely-spaced trabeculae than most other regions analyzed. Although some regional differentiation is apparent, the broad similarities in trabecular bone developmental trajectories may reflect a generalized, genetically-influenced patterning independent of external mechanical stimuli.

Grant Support: NSF BCS 1028904 (TMR), 1028793 (JHG), and 1028799 (DAR).