The present invention relates to a thoracic spine posterior transpedicular screw finder that guides a drilling device quickly to the exact position for drilling purpose onto vertebra, secures the drilling process and prevents it from deviation in spinal instrumentation with the transpedicular fixation...http://www.google.de/patents/US20040073229?utm_source=gb-gplus-sharePatent US20040073229 - Thoracic spine posterior transpedicular screw finder
