Ex-vivo evaluation of the three-column concept in canine thoracolumbar fractures

Abstract

Traumatic events such as a motor vehicle accident or falling from heights are very common in veterinary medicine and often lead to vertebral fracture-luxation with concomitant spinal cord injuries, mostly in the thoracolumbar spine. The purpose of this cadaveric biomechanical study was to determine the feasibility of the three-column concept in canine thoracolumbar segments with induced fractures. Eighteen Functional Spinal Units (FSU) of the thoracolumbar segments (T12-L2) were collected from 18 medium-sized adult dog cadavers and were subjected to flexion-extension and lateral bending tests so that range of motion (ROM) was recorded with a goniometer. Fractures were induced by compressive loads applied by a universal testing machine (EMIC®). After this, specimens were screened using computed tomography (CT) and the fractures were graded as affecting one, two or three columns, and divided into groups A, B, and C, respectively. Post-fracture range of motion (ROM) was compared with the previous results. Groups B and C (with fractures in two or three columns) had instability in the two axes evaluated (P<0.05). The outcomes of this study support the applicability of the three-column theory to thoracolumbar spines of dogs, as the FSUs that suffered fractures in two or more columns showed axial instability.

Schiff‐Sherrington syndromein a 7‐year‐old zebra mare (Equus quagga)

“…For this purpose, the vertebral body is artificially divided into three compartments – ventral, middle and dorsal. If two of the three compartments are damaged, a fracture is considered unstable (Diamante et al., 2020). In the case presented here, an acute traumatic fracture of all three compartments of the 7th thoracic vertebra was diagnosed on radiographs performed in lateral recumbency.…”

“…For this purpose, the vertebral body is artificially divided into three compartments -ventral, middle and dorsal. If two of the three compartments are damaged, a fracture is considered unstable (Diamante et al, 2020).…”

“…A thin, slightly irregular radiolucent line in a dorsal to ventral direction through the cranial half of the vertebral body of T7 was visible, ending at the ventral margin with a short reverse Y‐shape and a small bony fragment. A mild dorsal subluxation of the vertebral body and an involvement of the dorsal compartment of the 7th thoracic vertebra were suspected due to trauma (Diamante et al., 2020; Shores, 1992).…”