SIGNALMENT:
4 year old male, mix-breed dog which the owner’s acquired at approximately
one year of age.
HISTORY:
Right rear lameness of 2 ½ months duration.
DIAGNOSIS:
The lameness was non-responsive to anti-inflammatory medication, and
radiographs of the limb showed a lesion in the mid-shaft of the right femur
(Figures 1 and 2). Referral for further evaluation was made.
Review of the radiographs prompted a suspicion of rupture of the cranial
cruciate ligament based upon the position of the femoral condyles in relation
to the tibial plateau (Figure 1). The femoral lesion was suspected
to be an old fracture which has healed as a malunion, and not related to
the current problem except for the anatomical abnormalities it created.
On physical examination, a positive cranial drawer sign was elicited.
TREATMENT:
A grade IV medial patellar luxation and a complete tear of the cranial
cruciate was found at surgery. The patellar luxation was most likely
chronic and related to varus deformity secondary to malunion of the femoral
fracture. A “false trochlear groove” can be seen where the patella
was located, medial to the true trochlear groove pointed out by the hemostats
(Figure 3).
|
Figure 2
Ventrodorsal view of the pelvis. The abnormal angulation of
the right stifle joint is appreciated and the right femur appears shorter
than the left.
Figure 1
Lateral view of the right femur. Note the midshaft lesion
and the relationship of the femoral condyles to the tibial plateau. |
