Microcracks formed in bone are due to fatigue and cyclic loading. This formation is associated with a reduction of bone resistance to fracture. However, the significance of the parameters that govern microcrack behavior is not yet fully explored. A two-dimensional micromechanical fiber-ceramic matrix composite material model of the osteonal cortical bone is presented in this paper. The solution for the edge dislocations as Green's function, is adopted to formulate a system of singular integral equations for the general microcracks in vicinity of the osteon. The effects of microstructural morphology and heterogeneity of the bone upon the fracture behavior is investigated by computing the Stress Intensity Factor (SIF) near the microcracks tips. Analysis of microcracks interaction indicates the significance of microcracks configuration in the shape of either stress amplification or stress shielding.