Application of a Novel Patient-Specific 3D-Printed Drill Guide for Cervical Transpedicular Screw Placement in Dogs: An Ex vivo Study

Introduction: Anatomical variations and eventual vertebral malformations render precise implant placement an even greater challenge in veterinary patients. Fluoroscopic guidance and the use of neuronavigation systems considerably improve implant placement accuracy, but it exposes the surgeon and the patient to significant levels of radiation. The aim of the present study was to evaluate the precision of a new surgical drill guide model printed in 3D to assist in directing cervical transpedicular screw placement.

Materials and Methods: 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 a patient-specific virtual perforation surgical guide (GP3D) based on the safe corridor of the vertebral pedicle for placement of 2.7 mm screws. Next, the GP3D were printed in 3D by the SLA method. Pedicular screws were applied with the aid of the GP3D in two groups: cadaveric vertebrae (GEX) and ABS-printed biomodels (GBIO). After implantation, both groups underwent CT again and the images were exported to a program to assess the transverse angle of the perforations.

Results: There were no significant differences between the angles of the trajectories of the screws between control group and GEX (p >0.05) and GBIO (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).

Discussion/Conclusion: Our hypothesis was confirmed once the 3D-printed patient-specific drill guide can potentially help guide the drill for screw drilling in the caudal cervical vertebral pedicle in dogs.

Acknowledgement: This study was funded by Fapesp (2018/248594).

Publication History

Article published online:
26 October 2022