Computed Tomographic Evaluation of Safe Corridors for Pin Placement in Rabbit Thoracolumbar Vertebrae and Sacrum

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

Authors' Contribution

M.C. and T.A.M.H. contributed to the conception, study design, acquisition of data, data analysis and interpretation. A.G. contributed to data analysis and interpretation. K.A.K. contributed to study design, data analysis and interpretation. P.E.H contributed to the conception and study design. All authors drafted, revised, and approved the submitted manuscript and are publicly responsible for the relevant content.

Publication History

Received: 18 April 2022

Accepted: 11 October 2023

Article published online:
15 November 2023

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