Implantation Corridors in Canine Thoracic Vertebrae: A Morphometric Study in Dogs of Varying Sizes

Abstract

Objective Surgical stabilization to treat fractures, luxations, and congenital malformations in the thoracic spine can be difficult due to its unique anatomy and surrounding structures. Our objective was to document the morphometrics of the thoracic vertebrae relating to an ideal trajectory for dorsolateral implant placement in a variety of dog sizes and to assess proximity to important adjacent critical anatomical structures using computed tomography (CT) studies.

Study Design Medical records for 30 dogs with thoracic CT were evaluated. Implantation corridor parameters for thoracic vertebrae (T1–T13) were measured, including the length, width, angle from midline, and allowable deviation angle for corridors simulated using an ideal implant trajectory. The distances from each vertebra to the trachea, lungs, aorta, subclavian artery, and azygos vein were also measured.

Results Implantation corridor widths were often very narrow, particularly in the mid-thoracic region, and allowable deviation angles were frequently small. Distances to critical anatomical structures were often less than 1 mm, even in larger dogs.

Conclusion Thoracic implantation requires substantial precision to avoid breaching the canal, ineffective implant placement, and potential life-threatening complications resulting from invasion of surrounding anatomical structures.

Keywords

spinal stabilization - spinal fracture - spinal subluxation - spinal malformation - computed tomography

Ethical Approval Statement

This study was conducted on CT images previously obtained and archived during the course of a routine diagnostic evaluation in canine patients. Institutional Animal Care and Use Committee (IACUC) approval is not required for such studies at our institution.

Note

This study was presented in part at the American College of Veterinary Internal Medicine Annual Forum, Austin, Texas, United States, 2022 (poster).

Authors' Contribution

J.C.S. contributed to the study design, identified cases, performed the morphometric analyses, interpreted and analyzed the results, and wrote and revised the manuscript. C.L.M. designed the study, interpreted and analyzed the results, and wrote and revised the manuscript.

Publication History

Received: 16 January 2023

Accepted: 15 December 2023

Article published online:
22 January 2024

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