The spine is performing three very fundamental functions: supporting (for braincase and shoulder and pelvis girdle), protecting (for core and roots of a spinal nerve) and motor activity (insertion place of head and neck, trunk and limbs muscles). The spine the main movement organ, which is submitted of variable and complex static and dynamic loads. Correct distribution of load ensures the proper formation of anatomical characteristic in osteo–muscular system and the correct functioning of spine. The majority of pathological changes are observed in the lumbar part of spine. In this part of spine, maximum loading forces influencing the vertebras and intervertebral discs, are observed. It’s connected with the presence of human’s centre of gravity located at this level [1–5].
Pathological changes and injuries of spine after communication accident or extreme sports are realized with the use of spine stabilizers. From the beginning of 80’s the wide use of transpedicular screw systems is observed. The transpedicular stabilization system of spine enables treatment of thoracic, thoracic – lumbar and lumbar segment of spine by posterior surgical approach. Geometric features of stabilizers’ elements match individual anthropometric features of patients. Implants which are used can immobilize the sick part of spine and let achieve the stable adhesion [1, 4 – 9].
More often, in order to verify the numerical analysis, the experimental analysis were carried out. They are showed the correct mechanical properties of metallic biomaterials and geometrical features of implants.