A Cadaveric Study Comparing Standard Fluoroscopy With Fluoroscopy-Based Computer Navigation for Screw Fixation of the Odontoid

Although direct osteosynthesis of certain types of odontoid fractures may increase union and decrease
the need for prolonged immobilization, screw fixation remains a technically demanding procedure.
This study compares radiation exposure, surgical time, and accuracy of hardware placement using
standard fluoroscopy versus computer-assisted fluoroscopy-based navigation (‘‘virtual fluoroscopy’’)
to assist with the placement of odontoid screws. Twenty-two cadavers were divided into two groups
and underwent placement of a single odontoid screw using either standard fluoroscopic or virtual
fluoroscopic guidance. Following screw placement, dissection of the C1–C2 segments was performed
to assess accuracy. A significant reduction in fluoroscopy time was noted with the computer-based
fluoroscopy technique, whereas the surgical time was not found to differ significantly between the
techniques. No critical breaches (those risking neurovascular injury) were noted in either group, and
the rate of noncritical breaches did not differ. The authors conclude that fluoroscopy-based virtual
navigation appears to have a safety profile similar to standard fluoroscopy while allowing a reduction in
radiation exposure. (Journal of Surgical Orthopaedic Advances 14(4):175–180, 2005)
Key words: cervical spine, fluoroscopy, internal fixation, odontoid fracture, osteosynthesis, virtual
fluoroscopy