Posterior fixation and fusion of unstable Hangman’s fracture by using intraoperative three-dimensional fluoroscopy-based navigation

The purpose of this study was to assess the efficacy and accuracy of posterior screw fixation for unstable Hangman’s fracture using intraoperative 3D fluoroscopy-based navigation.

14 patients with unstable Hangman’s fractures (11 males and 3 females), ranging in age from 21 to 59 years, received posterior fixation assisted by an intraoperative 3D fluoroscopy-based navigation system: 11 Levine–Edwards type II and three type IIA cases. The American Spine Injury Association grade was D in 2 and E in 12 cases.

Operation time was 110 min (range 90–140 min). Hospital stay was 7.6 days (range 5–12 days). All the patients were observed for an average of 28.8 months (range 15–50 months). No screw-related injury to nerve, or vertebral artery was observed intraoperatively. An average of four screws/patient were inserted. Pedicle screws were placed into C2 and C3, and 5 screws were into the lateral mass of C3. Screw placement accuracy was evaluated using postoperative CT, according to the modified classification of Gertzbein and Robbins; one screw was grade 2 in C2, and three screws were grade 2 in the pedicle of C3. No grade 3 misplacement or clinical deficits were noted. C3 lateral mass screws were successfully inserted. Neck pain was relieved in each case. Neurologic status improved from D to E in 2 cases. Solid fusion was demonstrated in all the cases by static and dynamic films during the final follow-up.

This case series demonstrates that intraoperative 3D fluoroscopy-based navigation is a safe, accurate, and effective tool for screw placement in patients with unstable Hangman’s fracture.