Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

704 Small Animal Radiolo g y and Ultrasono graphy
FIG. 6-54 A 6-month-old Labrador
Retriever was playing with its sibling
when it yelped and was noted to have
persistent neck pain. There is a misalignment
between C1 and C2 (white
arrow), with the dens fractured from
C2 and remaining in its normal place
in C1 (black arrow). Diagnosis:
Fractured dens.
FIG. 6-55 A 1-year-old female
domestic short-haired cat that was
hit by a car. A, The lateral radiograph
revealed fractures of the pedicles and
laminae of the caudal portion of L5.
There is an avulsion fracture of the
caudal endplate of L5. Continued
A
Extensional trauma usually results in avulsion fractures of the ventral spinal components
and shearing fractures of dorsal spinal components (Figs. 6-55 and 6-56). In flexional
trauma, the ventral vertebral body components will experience shearing forces and the
dorsal components will experience avulsive forces (Fig. 6-57).
Bursting fractures are caused by a massive force such as that caused by a gunshot
wound to a vertebral body. This results in complete dispersion of the vertebral fragments
(Figs. 6-58 and 6-59). This type of fracture is uncommon.
Dislocations. Trauma may bring rotational or complex forces to bear upon the spine
(Fig. 6-60). Subluxation or luxation of the spine may occur, with the dorsal facets of one
vertebra misaligned with those of the vertebra immediately cranial to it (Fig. 6-61).
Articular facet fractures may occur concurrently with luxation or subluxation, and careful
examination of the radiograph may be required to identify these small fragments.
When traumatic vertebral body luxation is present, concurrent vertebral body fractures
are more common than articular facet fractures. 238 A widened disc space may be the only