We present an evolutionary microstructural model to study the mechanical behavior of pathological Haversian cortical bone in the framework of linear elasticity. The Haversian cortical bone includes Haversian canals, osteons, cement lines, and interstitial bone. The composite microstructure is built using a Monte Carlo (MC) algorithm and initially displays a healthy morphology, which then evolves to mimic bone progressive aging, due to osteoporosis or low remodeling. The MC algorithm incorporates bone macroscopic morphological components such as porosity and osteonal volume fraction, microscopic parameters such as osteonal and Haversian canal diameter distributions, and also pathological growth laws characteristic of aging diseases. The local mechanical properties are measured by nanoindentation and microextensometry. The microstructures are discretised by a finite element 3D model to calculate the evolving representative volume element of aging bone, the macroscopic elastic bulk properties and microscopic strain and stress fields. The macroscopic anisotropy and local strain of aging bone are compared to those of healthy tissue in order to understand how morphological changes affect bone failure.