The goals of the Dyflex II spinal system is to restore the integrity of the spinal column and fix the fractures of spinal bone. Quality Dyflex ll is a device intended to be implanted consisting of Ti6AI-4V according to ISO 5832-3 and ASTM F136-98. Dyflex ll utilizes the state-of-the-art technology and apply the essential requirements of MDD 93/42/EEC and ISO 14630:1997 from the beginning stage of the device design to manufacturing and inspection. In developing the Dyflex ll the following design features are kept in mind - Evaluation Dyflex ll was evaluated by not only mechanical test but also simulation in virtual clinical conditions. Xena sponal system was mechanically tested in various conditions, such as compression, tension, torsion and fatigue.