Precision and trajectory of three-dimensionally printed animal-specific drill guide for cervical transpedicular screw placement in dogs: An ex vivo study

ABSTRACT The aim of this study was to evaluate the precision of a new surgical drill guide model printed in 3D to assist in directing cervical transpedicular screw placement. Five canine cadavers underwent computed tomography (CT). C5 and C6 cervical vertebrae were exported to three-dimensional (3D) reconstruction software, which allowed the creation of an animal-specific virtual perforation surgical guide (3DSDG) based on the safe corridor of the vertebral pedicle for placement of 2.7 mm screws. The 3DSDG were printed in 3D by the SLA method. Pedicular screws were applied with the aid of the 3DSDG in cadaveric vertebrae (specimens) and ABS-printed biomodels. After implantation, a CT scan was performed on the specimens and biomodels, the images were exported to a program to assess the transverse angle of the perforations. There was no difference between the screw trajectories angles in the species (p >0.05) and biomodels (p >0.05). The evaluation of screw trajectories by the three-dimensional reconstruction method and by computed tomography also showed no significant differences (p >0.05). Our hypothesis was confirmed once the 3D-printed animal-specific drill guide can potentially help guide the drill for screw drilling in the caudal cervical vertebral pedicle in dogs.