One third of cancer patients present vertebral metastases with possible neurological complications. SINS, a radiographic scoring system based on clinicians' visual estimates, is the current standard to evaluate the instability of a metastatic spine, despite its qualitative nature. This thesis is the starting point of project that aims to introduce in the SINS a personalized assessment of vertebral biomechanics, by means of subject-specific finite elements models (SSFE) built from CT images.The heterogeneity of modeling approaches and results present in the literature, indicates that no consensus has yet been reached, neither in intact nor in metastatic vertebrae. Starting from this consideration, a novel validation experiment was designed in the project.