The contribution of the cortical shell and endplate to the stiffness and strength of the vertebral body is not well understood. However, several studies have suggested that the cortical shell plays an important role in the fracture strength of the whole vertebral body as bone is progressively lost from the centrum due to aging and osteoporosis (Eastell 1991, Faulkner 1991, Kurowski 1986. Silva 1997). Silva et al. (1994) concluded that prediction of cortical bone geometry using computed tomography (CT) based measurements is subject to considerable uncertainly caused by image distortion and the low ratio of image resolution of 0.25 mm/pixel to cortical shell thickness (0.09–0.86 mm). Thus, in development of CT-based models of the vertebral body, particular attention should be paid to the details of shell modeling.