Page 276 - Canine Lameness

248 15 Shoulder Region

Arthrography, ultrasound, CT, and MRI have all been reported and evaluated for imaging osteo-
chondrosis/OCD. One study reported reasonable success at identifying cartilage flaps of OCD
lesions with arthrography and ultrasound, when the flap was not mineralized, and thus not identi-
fied radiographically (Vandevelde et al. 2006). Another study reported both ultrasound and MRI
had better sensitivity (but not specificity) than radiographs at accurately diagnosing the presence
or absence of shoulder OCD (Wall et al. 2015). CT is a frequently used imaging modality since it
allows rapid investigation of the two most commonly observed pathologies in juvenile patients:
shoulder OCD and elbow dysplasia. Furthermore, it aids to detect other, less commonly observed
differential diagnoses, such as panosteitis.
Arthroscopy is also an extremely valuable tool in diagnosing OCD, since it allows for evaluation
of the cartilage surface itself. It is also the only diagnostic method that allows therapeutic interven-
tion. Since most OCD lesions are readily identified on radiographs, clinicians will frequently proceed
to arthroscopy as the next diagnostic of choice, to also allow surgical correction of the disease.

15.10 Other Diseases Affecting the Shoulder Region

15.10.1 Caudal Glenoid Fragments
Lameness resulting from a fragment in the area of the caudal glenoid has been reported although
different terminologies have been used. The condition was originally described as accessory caudal
glenoid ossification center (Olivieri et al. 2004) whereas other authors have described it as “calcifi-
cation of the caudal rim of the glenoid” (Van Vynckt et al. 2013). Regardless, these caudal glenoid
fragments may be asymptomatic, if they are not freely movable. The fragment can be identified
radiographically (Figure 15.16), although advanced imaging is prudent to ensure other causes of
lameness are not present. Arthroscopic examination can identify the degree of mobility of the frag-
ment, further validating diagnosis. It can also be utilized to remove the fragment and is reported to
SHOULDER REGION 15.10.2 Glenoid Dysplasia
successfully alleviate lameness in some dogs (Olivieri et al. 2004).

Glenoid dysplasia (i.e. congenital shoulder luxation) describes a congenital deformity of the scapu-
lar glenoid cavity, which eliminates the normal articulation and stability of the shoulder joint. The
resulting consequence is usually medial shoulder luxation in juvenile dogs (Vaughan and Jones
1969). Cases are usually detected in dogs less than a year of age. Miniature and toy Poodles appear
to be a predisposed breed. Physical examination findings include a significant lameness to non-
weight-bearing function of the limb. On palpation, the humeral head is detected medial to the
scapula. Definitive diagnosis is accomplished with radiographs, which depict a distorted glenoid
cavity, displacement of the humeral head, and in some cases, a distorted humeral head (Figure 15.9).
Therapy may include surgical (excisional arthroplasty or shoulder arthrodesis) or nonsurgical
treatment, depending on severity. Identification of this disease process in a mature dog, that has
previously been asymptomatic, warrants a thorough investigation for other causes of lameness, as
this condition has been present for the life of the patient.

15.10.3 Adhesive Capsulitis
Adhesive capsulitis, also termed “frozen shoulder,” describes a condition of pain and loss of ROM
caused by fibrosis of the joint capsule and adhesion formation within the joint. In people, it may
arise spontaneously or secondary to other shoulder conditions or immobilization. Importantly, the
condition has been described to undergo multiple phases, including a final “thaw” phase, with