Radiological studies on the best entry point and trajectory of anterior cervical pedicle screw in the lower cervical spine.

Objective: To explore the best entry point and trajectory of anterior cervical transpedicular screws in the lower cervical spine by radiological studies, and provide reference for clinical application.

Methods: Fifty patients were scanned by computed tomography and confirmed no obvious defect of the cervical spine. On horizontal axis, camber angle (α) and axial length (AL) were measured from C3 to C7.

Proposed alternative revision strategy for broken S1 pedicle screw: radiological study, review of the literature, and case reports.

Background Context: There have been many reports outlining differing methods for managing a broken S1 screw. To the authors' best knowledge, the technique used in the present study has not been described previously. It involves insertion of a second pedicle screw without removing the broken screw shaft.