Shoulder Morphology

A variety of shoulder disorders are associated with the acromin. (GILL, MCIRVIN, KOCHER et al., 2002; TUCKER and SNYDER, 2004; HAMID, OMID, YAMAGUCHI et al., 2012) and its morphology is an important tool in pathology diagnosis. The shoulder is a complex joint that allows movements of flexion, extension, abduction, adduction, external and internal rotations. (Describe the anatomy of the joint- refer last, Grays anatomy)

Variations in the architecture of the acromium is the primary etiologic factor in impingement syndrome’s pathogenesis, leading to potential rotator cuff disease. The volume of the subacromial space is reduced due to differences in the development and morphology of the acromion, the presence of anterior acromial spurs and inferior

The anterior tip of the acromion, the coracoacromial ligament, and the coracoid process have been described as sources of impingement. The relationships of the supraspinatus tendon, the biceps tendon, and the greater tuberosity of the humerus with the coracoacromial arch were demonstrated through various arcs of shoulder motion in autopsy subjects. Biceps tendon impingement occurred predominantly against the lateral free edge of the coracoacromial ligament. Impingement of the supraspinatus tendon and greater tuberosity was demonstrated primarily against the acromial end of the coracoacromial ligament and the anterior tip of the acromion during arcs of flexion and internal rotation. Formation of traction osteophytes on the anterior acromion in patients with chronic impingement symptoms may due to stretching of the coracoacromial ligament by the greater tuberosity passing beneath it. This may explain the (Burns and Whipple,

In the last 7 years, they have treated 20 patients with a previously undescribed "keeled" acromion. The keel refers to a central, longitudinal, downward sloping spur on the acromial undersurface. Patients with a keeled acromion are at significant risk of bursal-sided as well as full-thickness rotator cuff tears. All patients in this series had significant bursal-sided tears, and 12 of 20 patients (60%) had full-thickness rotator cuff tears associated with an acromial "keel." In addition, patients with a keeled acromion are younger (average age, 52.7 years) than would be expected for patients with rotator cuff disease. Often these patients are misdiagnosed, and effective treatment is delayed. Diagnosis of a keeled acromion relies on a high level of suspicion, as well as knowledge of clinical and radiographic signs consistent with an acromial