Imaging Observation of Deformities and Injuries Affecting Posterior Screw Fixations after Hangman fracture

Abstract

Introduction Objective The aim of the study is to observe the incidence of C1 to C3 deformities and injuries in patients with hangman fracture that affected the placement of screws for posterior short-segment fixation. Materials and Methods Seventy-eight patients with hangman fracture were retrospectively reviewed with three-dimensional computed tomographic scans of bony structures. The C1 to C3 screw trajectory designs were performed in the workstation to identify the presence of any deformities or injuries that would preclude safe screw placement in these segments. Results The presence of regional deformities or injuries was identified in 21 cases (27%). Six (7.6%) cases were not fit for C1 posterior arch screw fixation, including small size of posterior arch in two cases and fractures of C1 posterior arch in four cases. Ten (13%) cases were precluded from C2 trans-pedicle screw placement, including small pedicle size and high riding of vertebral artery and fractured fragments encased into vertebral canal or transverse process foramen. Nine (12%) cases were precluded from C3 trans-pedicle screw fixation due to small pedicle size, sclerotic pedicle, and pedicle fractures or vertebral body fractures. Conclusion There is a high incidence of regional deformities and injuries in the C1 to C3 region after hangman fracture that affects the placement of posterior screws. Preoperative evaluation of these conditions using 3D-CT scans is of paramount importance for the choice of proper surgical technique and avoid risk of fatal complications. Disclosure of Interest None declared