Page 350 - Canine Lameness

322 19 Stifle Region

has a higher pitched, light crackling sensation, that can be audible as well as palpable. Unlike a
meniscal click which occurs only once during ROM, crepitus is most easily detected in the para -
patellar region around the trochlear ridges and is observable throughout the whole ROM of the
stifle joint.
The cranial drawer test elicits abnormal sagittal plane instability associated with CCLD and
is highly specific for rupture of the CCL, with a sensitivity of 86% and specificity of 98% (De
Rooster and Van Bree 1999c). The test can be performed with the patient standing or laying
down. Particularly larger dogs that are off-weighting the limb at a stance generally allow pal -
pation while standing. However, some dogs become tense, making it more difficult to assess
for instability. To perform the test, the examiner stabilizes the distal femur with one hand by
placing the tip of the index finger on the patella and the thumb on the lateral fabella. With the
opposite hand, the proximal tibia is grasped with the thumb placed in the region of the fibular
head and the tip of the index finger on the tibial tuberosity. The lower hand is used to first
push the tibia caudally (to reduce any present cranial tibial subluxation); the thumb is then
used to gently push the proximal tibia cranially (Figure 19.7). The lower hand also controls the
angle of the tibia relative to the femur. Ideally the trajectory of the movement of the tibia rela -
tive to the femur is parallel to the slope of the tibial plateau, to maximize the drawer motion
with minimal force or effort. If radiographs are unavailable (to estimate the tibial slope), the
STIFLE REGION ments to find the position of maximal instability and elicit a positive test. The drawer test
examiner can repeat the drawer test in flexion, increasing the angle of extension in 20° incre -

should always be performed in both flexion and mild extension. Note that the collateral

(A) (B)

Figure 19.7 The cranial drawer test is performed by (A) placing the index finger on the patella and the
thumb on the lateral fabella, with the opposite hand, the proximal tibia is grasped with the thumb placed
caudal to the fibular head and the tip of the index finger on the tibial tuberosity. The lower hand is then
used to (B) gently push the proximal tibia cranially, which indicates CCLD deficiency.