This study develops a three-dimensional FE model of the C4-C6 unit of the cervical spine, with nonlinear material properties of the joints and stabilized with an anterior fixation system, after a simulated injury. The model of the 3 vertebrae, the fixation plate and bone screws included non-linear definition of the ligaments and discs. Appropriate material properties from the literature were used. The motion characteristics of the spine segment, as well as the stiffness and strength of the stabilized unit, were compared with available experimental data. Cleary the fixation system replicates the intact spinal segment in static compression tests under a standard head's weight but improvements are necessary to design a more biomechanically relevant fixation system. The FE method proved to be essential for this kind of biomechanical analysis, and the model will be used in further investigations.