Page 266 - Canine Lameness

238 15 Shoulder Region

degenerative condition. However, rupture of the biceps tendon may be acute and can produce
similar symptoms. Nonetheless, rupture of the biceps tendon is rare and presumed to be of trau-
matic etiology, which can occur within the substance of the tendon or as an avulsion from the
supraglenoid tubercle (Figure 15.5). Complete rupture may be asymptomatic, as the strain on the
injured tissue has been released (Wiemer et al. 2007).
Biceps tendinopathies may be classified as calcifying (i.e. if bony mineralization is present within
the tendon) or non-calcifying, thereby indicating whether the pathologic changes include calcifi-
cation of the muscle or tendon. This is particularly important from a diagnostic point of view since
non-calcifying tendinopathies can be missed if radiographs are used as the only diagnostic tool.
Calcifying tendinopathy implies chronicity. Although it is an anticipated progression of unad-
dressed disease (Bardet 1999), ambiguity remains in the literature as to whether this is a subset of
biceps tendinopathies, or its own entity.
Nonsurgical management (e.g. restricted activity, anti-inflammatories and rehabilitation, and
joint injections) or surgical treatment (e.g. biceps tendon release or tenodesis) has been reported
(Bergenhuyzen et al. 2010). If secondary biceps tendinopathy is present, the primary condition
should be addressed. For example, if impingement of the biceps tendon by the supraspinatus is
present, treating the supraspinatus may alleviate the symptoms associated with the biceps.

15.6.1 Signalment and History
Biceps disease is largely associated with large-breed, active dogs, which are middle-to-older aged.
Apart from biceps rupture, a specific traumatic event is rarely noted. The patient may present with
an acute thoracic limb lameness, a chronic lameness that worsens with activity, or an intermittent
lameness. Lameness is generally weight-bearing particularly with chronic cases, but a non-weight-
bearing lameness may be observed with acute tears. Noting the chronicity may give some assis-
tance in choosing an appropriate therapeutic option and predicting prognosis.
SHOULDER REGION 15.6.2 Physical Exam

External structures that can generally be distinguished on physical examination of the shoulder
region include the tendon of the biceps brachii, the infraspinatus, supraspinatus, triceps and del-
toid muscles, acromion, scapular spine and body, and the greater tubercle of the humerus. The
biceps tendon may be palpated on physical exam by identifying its site of origin, the supraglenoid
tubercle on the cranial margin of the articular space. A round, thick tendon should be palpable
coursing distally from the supraglenoid tubercle, crossing the bicipital groove of the humeral head
(Figure 15.10). The supraspinatus tendon is more lateral than the biceps but covers the medially
located biceps origin substantially in some dogs (Figure 15.10). Additionally, the transverse liga-
ment covers the origin complicating palpation of the biceps origin. Care should be taken to identify
the correct tendon when possible. If the patient is well muscled, or over conditioned, palpation
may be challenging, and flexion of the shoulder may aid in identifying this structure.
Muscle atrophy of the shoulder, producing a prominent scapular spine, may be present in
chronic lameness cases as frequently seen with biceps tendinopathy. However, this is an unspecific
finding, and a tentative diagnosis of biceps tendinopathy based on physical exam is most com-
monly based on a pain response during manipulation. The sensitivity of the patient’s response to
shoulder manipulation and biceps brachii palpation is highly variable and likely dependent upon
severity, chronicity, and patient disposition. More severely affected individuals may react merely to
palpation of the biceps tendon origin. Many will respond to palpation of the tendon, while the
shoulder is flexed and the elbow simultaneously extended, placing the greatest strain on the tendon
(Figure 15.11 and Video 3.1). This test is generally known as the “biceps test” and palpation of the