Advances in the Canine Cranial Cruciate Ligament, 2nd edition

124 Clinical Features

MC

Figure 17.1 Arthroscopic image of the intercondylar
notch region of the distal femur of the right stifle of a
7-year-old neutered female mix-breed dog with a stable
stifle and very mild stifle arthritis radiographically. Mild
disruption of some of the fibers of the caudal cruciate
ligament is evident, particularly adjacent to the femoral
attachment site (arrows). MC, medial condyle.

with CR. Caudal displacement of the tibia rel-
ative to the femur may be evident on a lateral
radiograph of the stifle (Soderstromet al. 1998).
Unless magnetic resonance imaging (MRI) of
the stifle is performed, a specific diagnosis is

MC

Figure 17.2 Photograph of the intercondylar notch
region of the distal femur of the right stifle of a 1-year-old
neutered male Labrador with an unstable stifle, moderate
arthritis, and rupture of the cranial cruciate ligament.
Complete disruption of the cranial cruciate ligament
(arrowheads), together with partial rupture of the caudal
cruciate ligament, with disruption of ligament fascicles
was found at surgery (arrow). MC, medial condyle.

most likely to be made during arthroscopy or

arthrotomy of the stifle (Johnson & Olmstead

1987). In dogs with CaCL rupture, ligament

degeneration and inflammation, and rupture of

CrCLfibers is typically present in many affected

dogs. These dogs are essentially affected with

CR (Sumneret al. 2010). Menisci are typically

intact in dogs with isolated CaCLrupture (John-

son & Olmstead 1987).

Avulsion fracture

Dogs with an avulsion fracture of the prox-

imal or distal attachment site of the CaCL

are usually young patients presented with a

clear history of trauma and a persistent lame-

ness (Reinke 1982). Stifle swelling and instabil-

ity is often detected on physical examination.

Avulsion fracture fragments are usually evident

radiographically, with careful examination of

high-quality radiographs. However, if an avul-

sion fracture fragment is identified radiographi-

cally, it may be difficult to determine which cru-

ciate ligament it is associated with.

Multiple ligamentous injuries to the stifle

In dogs with severe stifle trauma and disruption

to multiple stifle ligaments, the CaCL is rup-

tured in more than 80% of patients (Aron 1988).

The presence of CaCL rupture is often masked

by stifle instability because of disruption to

other supporting structures, such as the CrCL

and the medial collateral ligament (Hulse &

Shires 1986; Aron 1988).

Treatment

In dogs with isolated CaCL rupture the need

for surgical treatment is unclear, particularly as

experimental transection of the CaCL does not

lead to lameness. Although various extracap-

sular and intra-articular stabilization methods

have been proposed, objective long-term eval-

uation of these procedures is lacking (Harari

1993). If tibial plateau leveling osteotomy

(TPLO) surgery is planned as a treatment for

CR, it is particularly important to determine

whether caudal drawer motion may be present

before surgery, and whether substantial CaCL