[CT Guided Stabilization of Fractures of Upper Thoracic Spine (Th 2-5) by Internal Fixator.]

The authors suggest a new method of stabilization of upper thoracie spine (Th 2 -Th 5) by an internal fixator. A safe and precise insertion of screws into the vertebrae from the posterior approach is performed by CT guided surgery.The surgery is carried out in a CT examination room providing conditions corresponding to an operating theatre. Of vital importance is the presence of an experienced roentgenologist. The screws are inserted through the basis of the transverse process and are firmly fixed in the verteral body. In case of a too narrow pedicle, its laterla wall usually gets broken and dislocated laterally. However, such an impairment of pedicle occurs in the region covered by the rib neck and head and ligaments which unite the rib with the pedicle and transverse process. These structures separate safely the course of the screw canal from the thoracic cavity. The inserted screw holds firmly two fixed points, i. e. the transverse process and the vertebral body.This is the main difference from a standard surgery where the main load bearing element is the pedicle. However, the stability of the screw inserted in this way is in the region of upper thoracic spine fully adequate. CT guided insertion of screws allows preoperative examination of the anatomy of vertebra and selection of the optimal direction of screws with regard to anatomical structures, as well as the choice of exact length of screws. In the course of the surgery it is necessary to monitor continuously both the direction and placement of the instruments and screws being inserted by a repeated CT examination. The surgery should be accomplished by a careful control of the final placement of screws, their fixation in the vertebral body and the distance of the tip of the screw from the anterior aspect of the vertebral body. The mentioned method has been successfully applied in 7 patients. Key words: upper thoracic spine, pedicle screws, CT guided surgery.