Computed Tomography (CT) of the Stifle 149(A)(B)Figure 20.12 (A) Radiographs of a 14-month-old Great Dane with an avulsion of the origin of the long digital extensor.
On the medio-lateral and caudo-cranial views a radiodense shadow (white arrows) can be identified in the lateral aspect
of the stifle, the origin of which is unclear. (B) Corresponding transverse, and sagittal and dorsal reconstructed CT images
showing this opacity originating from the tendon of origin of the long digital extensor (white arrow).
the menisci, but the use of CTA, if performed
correctly, can help in decision-making. In some
patients with stifle problems, a fragment or
calcified structure can be detected on radio-
graphs. CT helps to clarify the origin of such
fragments, and is very useful for diagnosing
avulsions of the CrCL in young dogs. Avul-
sion of the CrCL is rare and is thought to be
a disease primarily of skeletally immature
dogs. In these animals, ligamentous attach-
ment to bone is stronger than the immature
bone itself, allowing avulsion to occur under
a force that is insufficient to cause actual
rupture of the ligament. This diagnosis is
clinically important as the avulsed fragment
may be re-attached if large enough, and
consequently the CrCL can be saved in these
young dogs.