Front Matter

306 Canine Sports Medicine and Rehabilitation

joint  capsule thickening, effusion, subscapularis
tendon, and medial glenohumeral ligament
pathological changes. Based on the results of
the  orthopedic evaluation and musculoskeletal
ultrasound findings, an arthroscopy may be con­
sidered. Arthroscopy allows for direct observa­
tion of the major intra‐articular structures with
magnification, dynamic evaluation of tissues
during shoulder ROM tests, and palpation of
intra‐articular tissues using arthroscopic instru­
mentation. Arthroscopic exploration with evalu­
ation of intra‐articular structures provides a
definitive diagnosis of MSS, as shown in Figure
12.14 (Devitt et al., 2007; Sager et al., 2009).

Treatment

Based on the results of the orthopedic examina­
tion, abduction angle tests, and arthroscopic
scoring, patients are placed into one of three
treatment categories: mild, moderate, or severe.

Mild MSS

Mild pathological changes include inflamma­
tion without fraying, disruption, or laxity of
the medial glenohumeral ligament and sub­
scapularis tendon and joint capsule (Figure
12.15). Patients with mild MSS are placed in
a  shoulder support system or hobbles and

prescribed rehabilitation therapy (Marcellin‐

Little et al., 2007).

Moderate MSS

Most MSS cases seen by one author (SC) in

performance, working, and active dogs are

moderate. Arthroscopic findings include sub­

scapularis tendinopathy (disruption, fraying,

core lesion), medial glenohumeral ligament

lesions (fraying or disruption; Figure 12.16),

craniomedial joint capsule focal synovial pro­

liferation and/or disruption, and labral lesions

(fraying, disruption, tears). In some cases

where there is a concurrent supraspinatus ten­

dinopathy (62% of cases; Canapp et al., 2016a),

a bulge of the supraspinatus tendon with

impingement on the biceps tendon may be

found. Arthroscopic treatment will vary

depending on the tissues involved and the

severity of disease. Treatment may include

radiofrequency‐induced thermal capsulor­

rhaphy (RITC). This technique has altered sig­

nificantly in recent years due to the detrimental

effects that can occur with aggressive applica­

tion (Cook et al., 2005b). A single‐pass striping

technique, developed based on current appli­

cations in humans, is currently used instead of

the previous multipass paintbrush technique

Figure 12.14 Arthroscopic image of a disrupted medial
glenohumeral ligament (arrow) and subscapularis tendon.

Figure 12.15 Arthroscopic image demonstrating mild to

moderate disruption/fraying, hypertrophy, and

neovascularization of the subscapularis tendon (arrow)

(mild medial shoulder syndrome).