Fracture mechanics can be understood as the area of science that studies the propagation of fractures, cracks, slits, and other flaws from mechanical processes that may negatively affect the strength of the material. Traditionally, the concepts on which the strength of the materials are based do not consider the toughness to fracture of the material, which can be defined as the property that quantifies the resistance to crack propagation. The essence of these studies can be applied to any type of material, such as in the medical field when studying the behavior of bone fractures. This type of fracture usually arises through high-energy trauma. Bone, under normal conditions, can support loads and absorb this energy. However, if there is a high level of energy associated with the trauma, the bone cannot support it and ends up suffering a fracture. This paper aims to develop a numerical microscale analysis of a bone fracture using the Extended Finite Element Method (XFEM). This dissertation studies two-dimensional simulations of the initiation and propagation mechanisms of an initial fracture in a compact bone unit called the osteon, which is bounded by the cement line, a zone that is low in type 1 collagen. In this way, it was possible to understand that the cement layer plays a role of containment, allowing greater deformations before rupture in the propagation of the microscale fracture, in addition, it was also verified that osteons in the transverse position have the greatest rigidity, while in the longitudinal position they have the most ductile models were found, due to the influence of the Haver channel.