Page 265 - Canine Lameness

15.6 ­iceps ­rachii Tendinopathy 237

15.5.1 Signalment and History
Shoulder luxation is generally a consequence of trauma (e.g. vehicular accident), therefore any dog
may be affected. In some cases, the history (including knowledge of any trauma event) may be
unknown. A thorough investigation into preexisting lameness may be indicated, particularly if
congenital conditions are considered as differential diagnoses.

15.5.2 Physical Exam
The physical exam on patients with traumatic luxation should prioritize systemic stability of the
patient, given vehicular trauma is likely to create other comorbidities. The luxation itself may be
challenging to appreciate if there is a large amount of soft tissue swelling. The limb is frequently
non-weight-bearing, with flexion of the elbow. The distal limb may be in abduction (medial luxa-
tion) or adduction (lateral luxation). When palpable, the acromion and the greater tubercle of the
head of the humerus will have increased distance between them, relative to normal. Palpation of
these structures on the contralateral limb can give a reference of a “normal” spatial relationship
between landmarks. Patients will be resistant to normal ROM of the shoulder joint. If luxation is
achieved, severe crepitation throughout manipulation may be noted. Increased abduction may be
appreciated for medial luxation, and for very unstable joints, the humeral head may palpably shift
in multiple directions relative to the scapula (e.g. the examiner may elicit cranial drawer with
cranial instability).

15.5.3 Diagnostics

Radiographs clearly demonstrate dislocation of the humeral head from the glenoid cavity
(Figure 15.9). Radiographs should be assessed for any evidence of fractures or underlying/preexisting
disease. In contrast to animals with congenital conditions (glenoid dysplasia), the radiographic
appearance of the humeral head and glenoid cavity are normal. Further diagnostics are rarely
needed to diagnose the problem, unless mild instability, rather than a true luxation is suspected. If
the joint is extremely unstable, and the clinician is suspicious that the joint is continuously SHOULDER REGION
dislocating and reducing, fluoroscopy (if available) or serial digital radiographs may be utilized to
evaluate the relationship between the humeral head the glenoid cavity. Although MRI or ultra-
sound are generally not necessary, they may benefit assessing the extent of soft tissue damage as
well as aiding surgical planning.

15.6 Biceps Brachii Tendinopathy

Biceps tendinopathy is one of the more common etiologies of shoulder pain. As our diagnostic
capacity has grown and workups of shoulder disease become more advanced, there is question as
to whether this disease has been overdiagnosed (i.e. structural pathology may be an incidental
finding). This condition is frequently referred to as biceps tenosynovitis, although this terminology
may be inappropriate since an inflammatory component is not present in all cases (Gilley et al.
2002). Biceps tendinopathies can be primary or secondary in origin. Primary etiologies include
strains, sprains, or tears (i.e. a primary problem of the biceps brachii). Secondary etiologies include
impingement by extra-articular structures such as an enlarged supraspinatus muscle or intra-articular
structures such as loose bony, fibrous, or cartilage fragments (i.e. pathology of the biceps is
caused by a different underlying condition). In general, biceps tendinopathy indicates a chronic