Abstract
Objective The aim of this study was to identify safe corridors for pin placement in the terminal
thoracic vertebrae, lumbar vertebrae and sacrum of rabbits using computed tomography
(CT) in cadaveric models.
Study Design Computed tomographic imaging of 25 adult New Zealand white rabbit (Oryctolagus cuniculi) cadavers was evaluated. Safe insertion corridors at the cranial and caudal end cortical
sections (ECS) of the vertebrae were determined using a multiplanar reconstruction
software. Pins were placed to allow maximal bone purchase within the safe corridors.
Post-procedure CT imaging was performed to evaluate the pin position.
Results The median safe corridor height in the thoracic and lumbar cranial ECS (2.54 mm;
1.39–3.97 mm) was significantly lower than that of caudal ECS (3.98 mm; 1.66–5.53 mm;
p < 0.001). The mean widths of the left and right sacral safe corridors were not significantly
different. Of the 99 pins placed, 70.7% of the pins were appropriately placed without
vertebral canal impingement. Errors included partial canal impingement (12.1%), complete
canal impingement (5.1%), inadequate bone purchase (7.1%), placement into the intervertebral
disc space (1.0%) or in the incorrect ECS than intended (4.0%). The odds ratio of
successful pin insertion without canal impingement was 2.77 (95% confidence interval,
1.04–7.43; p < 0.05) times higher in the caudal ECS than in the cranial ECS.
Conclusion The corridor identified in this study can be used as a guideline for pin placement
in the thoracic and lumbar vertebrae of New Zealand white rabbits. Further biomechanical
studies are required.
Keywords
rabbit - computed tomography - pin insertion - fracture and luxation - vertebrae
