Microcracks are thought to play an important role in bone fracture behavior and bone remodeling. They were shown to reduce fracture resistance of bone and are supposed to elevate fracture risk [Burr et al, 1997]. So far, microdamage has been mainly analyzed qualitatively and quantitatively using twodimensional (2D) techniques not accounting for the three-dimensional (3D) nature of microcracks. Yet, 3D approaches are mandatory for a better understanding of the failure process. Recently, we have introduced [Voide et al, 2006] image guided failure assessment (IGFA) of murine cortical bone under static compressive load using synchrotron radiation (SR)-computed tomography (CT). Figure 1 shows the capability of SR-based CT making it possible to relate ultrastructural features such as the cannular network or the osteocyte lacunar system to the initiation and propagation of microcracks. However, the underlying mechanisms involved in post-yield and failure behavior of bone are still poorly understood. Furthermore, static IGFA experiments gave only time-discrete snapshots of the dynamic failure process (see Figure 2a).