Advances in the Canine Cranial Cruciate Ligament, 2nd edition

Computed Tomography (CT) of the Stifle 143

(A)

(B)

Figure 20.3 (A) Sagittal reconstruction of a CT
arthrogram of the stifle of a 4-month-old mongrel dog.
The articular cartilage can be seen as a radiolucent line
parallel to the subchondral bone (black arrows). The
silhouette of the lateral meniscus can be appreciated as
well (arrowheads). (B) Transverse CT arthrogram image
where the silhouettes of the cranial and caudal cruciate
ligaments can be appreciated. LFC, lateral femoral
condyle; a, caudal cruciate ligament; b, cranial cruciate
ligament; c, menisco-femoral ligament.

encouraging (Tiverset al.2008), some clinical
studies performed in dogs have reported CTA
in the detection of naturally occurring meniscal
damage to be of limited value (Samiiet al.
2009). Although gross meniscal lesions (Figures
20.4 and 20.5B) and cruciate ligament damage
(Figure 20.5A) can be evaluated, the main prob-
lem with CTA is that in inflamed stifle joints
the injected contrast medium is very rapidly
absorbed and diluted, making accurate inter-
pretation of possible lesions difficult. Mixing
0.2 mg epinephrine with conventional contrast
agents in order to slow down any resorption
should be used (De Ryckeet al. 2015). For CTA,

Figure 20.4 Sagittal reconstruction of a CT arthrogram

of a dog after partial medial meniscectomy. The cranial

pole is seen to be missing (black arrow), and the caudal

pole seems to be crushed (white arrows).

the normal iodine concentration should be

reduced to 80–100 mg ml–1to reduce the risk

of contrast obscuring intra-articular structures.

The original contrast medium can be diluted

with saline, and for an average stifle joint a

volume of 4 ml is recommended. Care should

be taken to avoid the fat pad during the intra-

articular injection of contrast. Repeated gentle

flexion and extension of the joint should be

performed to enhance contrast dispersion.

CT features of different stifle

conditions

Developmental disorders

OC/OCD: OCD lesions have typical features,

being radiolucencies surrounded by a sclerotic

rim (Olstadet al. 2014). More lesions can be

detected by using CT, and more intra-articular

fragments can also be seen (Figure 20.6). The

status of the joint cartilage can be checked using

CTA (Figure 20.7).

In patella luxation the location of the patella

can be checked, the depth of the patellar