Densities of osteons and osteon fragments at the midshafts of the femur, tibia, fibula, humerus, radius, ulna and clavicle are examined in a sample of contemporary human males and females (n = 39; 23 female, 16 male), with comparative data derived from one specimen each of Gallus gallus and Felis silvestris catus. Results demonstrate that there are significant differences in mean complete and fragmentary osteon densities among bones and between the sexes. We suggest that these patterns are less a simple reflection of the so-called "Wolff's law," but instead represent not only remodeling in response to loading, but also underlying intrinsic developmental parameters specific to each bone. Given the diversity of locomotor patterns of the three species, and the resulting differences in loading environments of their limbs, this histomorphological pattern suggests that remodeling is an inherently complex phenomenon, subject to local intrinsic developmental factors in addition to mechanical loading.
Histomorphological and Geometric Properties of Human Femoral Cortex in Individuals over 50: Implications for Histomorphological Determination of Age-at-Death01/01/1994
Cortical area, area moment of inertia, and polar moment of inertia were determined from the midshafts of a series of 62 femurs (34 female and 28 male) from a U. S. white population, ages 51–95. The density of osteons and osteon fragments (per mm2) was also determined. Neither osteon nor osteon fragment density was significantly correlated with age. These variables were correlated, however, with normalized cortical and endosteal areas, normalized area moment of inertia, and polar moment of inertia. Osteon fragment numbers alone are not highly correlated with cross-sectional properties. This research suggests that osteon density and osteon fragment density are significantly related to cortical mass and distribution in older people, but are not a direct function of age in persons over 50 years of age. Histological age estimates in older individuals must, therefore, be used with extreme caution. © 1994 Wiley-Liss, Inc.