Abstract
Objective The aim of this study was to report new preoperative and intraoperative techniques
performed for canine thoracic or lumbar spine kyphosis stabilization using three-dimensional-printed
patient-specific drill guides, polyaxial titanium bone plates and drill stops, and
to determine the accuracy of screw placement using these techniques.
Study Design Retrospective study, five client-owned dogs.
Results Three-dimensional-printed patient-specific drill guides and drill stops allowed safe
drilling and screw placement in all of the cases, with (i) 84% of the screws graded
as I (ideal placement) and 16% as IIa, IIIa or IIIb according to the modified Zdichavsky
classification (partial penetration of medial pedicle wall, partial penetration of
lateral pedicle wall and full penetration of lateral pedicle wall respectively), (ii)
mean mediolateral deviation of ± 4.06 degrees (standard deviation: 8.21 degrees) compared
to planned trajectories and (iii) variation in screw depth of ± 2.29mm (standard deviation:
3.07mm) compared to planned depth.
Conclusion We believe that the techniques presented here for thoracic spinal stabilization in
dogs show promise; they allowed safe placement of screws along planned trajectories
and depth; they also removed the need to use polymethylmethacrylate, while the use
of titanium offers the possibility to repeat magnetic resonance imaging in these cases
with chronic spinal conditions.
Keywords
spine - 3D-printed drill guide - polyaxial titanium plate - drill accuracy - dogs
