Relationship between porosity and mineralization in the Haversian osteon

Cortical bone, at the osteonal level, consists of three phases: mineral, organic, and pore or void phases. In osteonal segments excised from mature human cortical bone, organic volume percent is a constant. Determination of the mineral and organic phase densities present in these segments has led to defining a simple relationship between percent mineralization and void volume. Studies of a group of osteonal segments from 5 human tibias suggest that porosity of up to 22.7% may exist. This is much more than is suggested by histological examination, leading to the conclusion that the majority of the void phase is present as a dispersed porosity.