Upper Extremities
21 Shoulder
Anatomy
humerus: body, head, anatomic neck, surgical neck, lesser tubercle, greater tubercle, intertubercular groove
scapula: coracoid process, acromion, glenoid cavity, medial border, lateral border, superior border, scapular spine, inferior angle, supraspinous fossa, infraspinous fossa, costal surface
clavicle: acromial extremity, body, sternal extremity, acromioclavicular joints (AC), sternoclavicular joints (SC)
Projections
[Part], PA or AP
CR Location
[Part], PA or AP –
Evaluation Criteria
External Rotation AP Evaluation Criteria: 1/3 of Humerus visualized. Greater tubercle seen in profile.
Internal Rotation AP Evaluation Criteria: 1/3 of Humerus visualized. Lesser tubercle seen in profile.
Inferosuperior Axial Evaluation Criteria: Relationship between glenoid fossa and humeral head seen. Lesser tubercle seen in profile.
Scapular Y Evaluation Criteria: Body of scapula seen on end, not superimposed by ribs. Humeral head superimposed over base of the Y.
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Hows & Whys of Shoulder Radiography
- What type of joint is the scapulohumeral joint?
- Diarthrotic, ball and socket
- What type of joints are the AC and SC joints?
- Diarthrotic, gliding
- Which position demonstrates the greater tubercle in profile?
- AP external rotation
- Which position demonstrates the lesser tubercle in profile?
- AP internal rotation
- How much of the humerus should be included on the AP shoulder images?
- The proximal 1/3
- Which views should be included if dislocation is suspected?
- Scapular Y and inferosuperior axial views
- In a normal scapular Y projection, where should the humeral head be seen?
- Directly superimposed over the junction of the Y
- Does external rotation of the humerus project the head of the humerus AP or lateral?
- AP
- Positioning the epicondyles perpendicular to the table top will result in which rotation of the shoulder?
- Internal rotation
- What three bones make up the shoulder girdle?
- Humerus, scapula, and clavicle
- What two bones make up the shoulder joint?
- Humerus and scapula
- In performing a supine study of the shoulder in either the internal of external rotation positions, how can you assure better contact of the affected shoulder with the image if the patient cannot lay perfectly flat?
- Raise the unaffected side on sponges until the affected shoulder contacts the table top. If the patient is kyphotic (hunchbacked), raise the hips until shoulder contacts table top.