Strain reduction between cortical pore structures leads to bone weakening and fracture susceptibility: An investigation using smooth particle hydrodynamics

Abstract

Age-related cortical pore structure in the Femur is critical to understanding mechanisms that relate to catastrophic hip failure. In the neck of the Femur about 70% of the strength is contributed by the cortical bone, which is the most highly stressed part of the structure and is the site where catastrophic failure is almost certainly initiated. A deeper understanding of age-related changes at this anatomical site is essential if an understanding of the mechanisms by which hips weaken and become vulnerable to fracture is to be gained. The aim of this study was to (i) examine a hypothesis that low strain low fields arise due to age related pore distributions causing bone absorption, and (ii) use a meshless Lagrangian particle-based computational modeling approach Smooth Particle Hydrodynamics' (SPH) to capture bone remodeling features at the particle level. The key findings from this study were firstly that bone remodeling due to strain at the osteon level generated pore merging and this increased with age. Secondly, SPH was shown to be successful at modeling the conversion between bone and marrow and the intricate pore shapes that evolved over time. © 2010 International Federation for Medical and Biological Engineering.