Front Matter

Chapter 14 Disorders of the Pelvic Limb: Diagnosis and Treatment 371

50–60% chance of rupturing the opposite CCL
(Buote et al., 2009).

Predisposition

Cranial cruciate ligament disease can affect
dogs of any breed, sex, or age, although a
higher incidence is reported for large‐breed
and overweight dogs (Duval et al., 1999).
Ligament degeneration is also associated with
aging, which occurs earlier in large breeds. The
Labrador Retriever, Newfoundland, Rottweiler,
Mastiff, American Staffordshire Terrier, Akita,
Boxer, and Bulldog are overrepresented, sup­
porting the likelihood of a genetic component
(Duval et al., 1999). To date, the Newfoundland
is the only breed that has identified chromo­
somal abnormalities associated with cruciate
disease (Wilke et al., 2006, 2009). Certain confor­
mation types (an upright stance or marked
varus of the pelvic limbs) have an increased
incidence of CCL disease. Neutered males and
spayed females are also at an increased risk
(Duval et al., 1999). Recently, a higher incidence
of cruciate disease was seen in female versus
male Labrador Retrievers, with an increased
incidence in dogs sterilized prior to 1 year of
age (Ekenstedt et al., 2017).

Clinical presentation

A rupture due to a traumatic event will initially
cause significant stifle effusion, and the patient
will be toe‐touching to non‐weight‐bearing
lame. In chronic cases, a precipitating event
may be associated with an acute notable change
in limb use; however, there is often a history of
intermittent lameness over a period of several
weeks to months. Common findings include
the patient sitting with the affected limb
extended or positioned laterally rather than
flexed and tucked under the body, shifting
weight off the affected limb when standing,
and displaying stiffness upon rising. Concurrent
meniscal injury can cause an audible click when
walking or flexing the stifle.
Partial CCL tears typically present with a
complaint of a mild weight‐bearing lameness
following heavy exercise, or stiffness following
prolonged periods of rest. Patients with bilateral

disease may shift weight back and forth between

the pelvic limbs when standing, shift weight to

the thoracic limbs, have difficulty or be slow in

sitting and rising, and may be exercise intoler­

ant. In some cases, the patient may be unable or

unwilling to bear full weight in either pelvic

limb, leading to possible misdiagnoses of a

neurological condition or hip dysplasia.

Diagnosis

Some dogs with chronic cranial cruciate disease

or partial CCL tears do not have significant

palpable stifle instability (cranial drawer or

tibial thrust test). However, most of these dogs

will have significant medial buttress and peri­

articular thickening of the stifle along with

decreased range of motion, particularly flexion.

Additional diagnostic tests, such as arthro­

centesis, MRI, ultrasound, and/or arthroscopy

may be recommended.

Arthroscopy is a minimally invasive technique

that allows for live, magnified, high‐resolution

assessment of the structures within the stifle

joint (Figure 14.22). The entire joint can be

examined via two or three stab incisions. This

not only increases the accuracy of a diagnosis,

but also reduces the morbidity and infection

rate associated with joint assessment as com­

pared with open arthrotomy (Hoelzler et al., 2004;

Pozzi et al., 2008).

Surgical management

Studies have shown surgical intervention to be

superior to medical management for CCL dis­

ease (Beaulieu & Pozzi, 2016; Hart et al., 2016).

Three categories of surgical stabilization exist:

intra‐articular grafting, extracapsular repair, and

corrective osteotomies. The grafting technique

has lost popularity, and a study concluded this

technique to have inferior results; thus, it will

not be covered in detail (Conzemius et al., 2005).

It is of note that substantial research is being

performed on intra‐articular grafting and this

method of stabilization may become a viable

option for the canine patient in the future. Of

the remaining techniques, osteotomies have

proven to be superior to extracapsular repair

for long‐term outcomes (Gordon‐Evans et al.,

2013; Nelson et al., 2013; Krotscheck et al., 2016).