Relation of collagen fiber orientation to some mechanical properties of human cortical bone

Abstract

The percentage of dark, light, and intermediate osteons and their fragments, as seen in polarized light, was determined for 53 cross-sections of embalmed, adult human bone. Dark osteons have collagen fibers predominantly parallel with the long axis of the osteon while in light osteons the fibers are at a sharp angle to the long axis of the osteon. Intermediate osteons are mixed.Significant positive correlations were found between dark osteons alone, as well as when combined with their fragments, and the single shearing strength. Intermediate osteons alone, and when combined with their fragments, showed significant positive correlations with the (1) single shearing strength, (2) modulus of elasticity, and (3) percent elongation.Significant negative correlations were found between light osteons alone, and when combined with their fragments, and the (1) single shearing strength and (2) modulus of elasticity.No other significant correlations were found among the various types of osteons alone, or when combined with their fragments, and the mechanical properties of the specimens.