Histomorphological Variation in the Appendicular Skeleton

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.