Fig. 1

Morphometric measurements of the subaxial cervical spine pedicle. a Axial image of C4 vertebra on computed tomography scan showing the pedicle axis length (A), pedicle length (B), interpedicular distance (C) and outer pedicle width (D). b Axial image of C4 vertebra on computed tomography scan showing the inner pedicle width (A) and transverse angle, which in this particular case was 43.4°. c Sagittal reconstruction image of the cervical spine at the level of C3 and C4 showing the superior pedicle distance (A), outer pedicle height (B) and inner pedicle height (C)