MECHANOBIOLOGIC INFLUENCES IN LONG-BONE CROSS-SECTIONAL GROWTH

We developed a computer model to simulate the interaction of biologica l and mechanobiological factors in the development of the cross-sectio nal morphology of long bones. The model incorporated a strong influenc e of biologically induced bone formation during early development. In addition, an assumed mechanical loading history during growth and deve lopment corresponding to age-related changes in body weight and muscle mass was applied. Based on the bone stress stimulus generated by the assumed loads, mechanically induced apposition and resorption rates we re calculated at the periosteal and endosteal surfaces using a previou sly developed bone modeling theory. These methods successfully emulate d the growth-related changes seen in long bone diaphyseal structure as well as changes observed in mature bones during aging. The simulation s recreated the rapid increase in bone dimensions during development, stabilizing at maturity, and then the gradual, age-related subperioste al expansion and cortical thinning. Throughout the growth, development , and aging simulations, the values of the bone radii, area, moments o f inertia, and apposition rates corresponded well with measurements do cumented by other researchers.