Front Matter

Chapter 12 Disorders of the Canine Thoracic Limb: Diagnosis and Treatment 303

Treatment

Conservative medical management and reha­
bilitation therapy are recommended for acute
cases. Conservative medical management
should include controlled activity, NSAIDs,
and cryotherapy. Intra‐articular injections
including hyaluronic acid, cortisone, PRP, or
stem cell therapy may also be considered
(Cookson & Kent, 1979; Gilley et al., 2002;
Marcellin‐Little et al., 2007; Wernham et al.,
2008). If a core lesion is noted, ultrasound‐
guided biological therapies (PRP, stem cell
therapy, or combination therapy) may be
considered.
Surgical treatment is recommended for
biceps avulsions or tears and for cases that are
nonresponsive to medical management and
rehabilitation therapy. Surgical treatment
includes arthroscopic reattachment for bony
avulsions or an arthroscopic release for severe
tendinopathies or tears.

Medial shoulder syndrome

A common cause of thoracic limb gait‐related
issues and lameness in performance, working,
and active dogs is MSS. This condition is simi­
lar to rotator cuff injuries in humans, including
ligament disruption, tendinopathy, labral and
capsular tears, or disruption. Such shoulders
are not unstable, instead they show evidence of

sprain and strain injury leading to discomfort

and dysfunction. Subscapularis tendinopathy

is the most common component of MSS.

The human thrower’s shoulder must be lax

enough to allow extremes of motion but secure

enough to provide stabilization of the shoulder

(Arrington & Miller, 1995; Slatter, 1985). The

same is true for the canine athlete that performs

many extremes of range of motion and requires

appropriate stabilization. Signs of MSS can range

from performance‐related problems such as

refusing tight turns to a weight‐bearing lame­

ness. MSS involves multiple components of the

shoulder joint and requires a thorough evalua­

tion to confirm. It is important to identify and

treat this condition early to obtain the best long‐

term results, and to prevent further sprain and

strain injury, which can lead to shoulder instabil­

ity and progression of osteoarthritis.

Cause

Medial shoulder syndrome is believed to be

related to chronic strain and sprain due to

repetitive activity or overuse rather than

trauma. Repetitive agility dog activities such as

jump–turn combinations and weave poles are

performed regularly during practice and at tri­

als. These maneuvers place the shoulder near

its end range of abduction (Figure 12.11) and

stress the soft tissue of the medial shoulder

complex. Mishaps on agility equipment or sim­

ply slipping on wet surfaces can also contribute

to the trauma inflicted on the shoulder. The

cumulative effects of the microtrauma occur­

ring to the shoulder structures can lead to per­

formance issues, discomfort, and lameness.

Overuse of the shoulder support structures can

lead to degeneration of the tissues, reducing

tensile strength and predisposing them to fray­

ing, disruption, and eventually complete break­

down (Maganaris et al., 2004; Marcellin‐Little et

al., 2007). When instability, subluxation, or lux­

ation occurs, a diagnosis of medial shoulder

instability is made.

Diagnosis

Presenting history will vary from avoiding

tight turns during performance to intermittent

thoracic limb lameness that worsens with exer­

cise and heavy activity. In some cases, a severe

Figure 12.10 Arthroscopic image of severe bicipital
tenosynovitis (arrow).