P143. CT- and Intraoperative 3D- Based Navigation of Pedicle Screws in Upper and Middle Thoracic Spine (T1-10)- Benefit or a Waste of Time?

BACKGROUND CONTEXT: Navigation of pedicle screws in the lower part of the thoracic, thoracolumbar and lumbar spine has become a well established method during the last years. But the accuracy of navigation was still insufficient for an exact placement of pedicle screws in the upper and middle part of the thoracic spine with thin pedicles.