🩺 Shoulder Radiography: Trauma Series & Specific Rotator Cuff Views

Survival Guide: Shoulder Radiography - Trauma & Rotator Cuff Series

The Bottom Line

• A comprehensive shoulder series requires at least three orthogonal views to fully evaluate for fracture and dislocation.
• For trauma, start with AP External Rotation and Scapular Y views. If dislocation is suspected, an Axillary view (or an appropriate alternative) is crucial.
• For rotator cuff pathology, specific views target different tuberosities and acromial morphology, often complementing advanced imaging like MRI.
• Always assess the relationship of the humeral head to the glenoid on all views.

Key Mechanisms

• Trauma:
  • Anterior Dislocation: Most common (approx. 95%), typically due to abduction and external rotation.
  • Posterior Dislocation: Less common, often associated with adduction, internal rotation, direct trauma, seizures, or electrocution.
  • Humeral Head Fractures: Direct impact, falls onto an outstretched arm (FOOSH).
  • Glenoid Fractures: Impaction from humeral head, direct trauma, avulsion.
  • Acromioclavicular (AC) Joint Dislocation: Direct fall onto the superior aspect of the shoulder.
• Rotator Cuff Pathology:
  • Impingement Syndrome: Repetitive overhead activities, often exacerbated by osteophytes or specific acromial morphology (e.g., hooked acromion).
  • Tendon Tears: Acute trauma (e.g., fall) or chronic degeneration, often in conjunction with impingement.
  • Calcific Tendinitis: Idiopathic, characterized by calcium deposits within rotator cuff tendons, frequently presenting with acute pain.

Trauma Series Views

AP External Rotation (Neutral/Slight External)

• Patient Position: Erect or supine, affected shoulder centered to the detector.
• Part Position: Arm slightly abducted, hand supinated, palm anterior. Ensure epicondyles are parallel to the detector.
• CR: Perpendicular to the detector, directed to a point approximately 1 inch inferior to the coracoid process.
• Key Anatomy: Humeral head in profile, greater tuberosity positioned laterally, glenoid cavity, proximal humerus, AC joint.
• Evaluation Criteria:
  • Optimal for showing proximal humerus fractures and calcification in the rotator cuff tendons.
  • Provides a general assessment of the alignment of the humeral head with the glenoid.

Scapular Y Lateral (True Lateral)

• Patient Position: Erect, patient rotated 45-60 degrees toward the affected side. Affected arm relaxed by the side.
• Part Position: The scapula must be perfectly perpendicular to the detector. Palpate the superior angle of the scapula and the AC joint to ensure correct obliquity.
• CR: Perpendicular to the detector, centered to the mid-scapular body, approximately at the level of the humeral head.
• Key Anatomy: Scapula in true lateral profile, humeral head superimposed over the 'Y' formed by the acromion and coracoid processes. The glenoid fossa is seen in profile.
• Evaluation Criteria:
  • Crucial for dislocations: The humeral head will appear anterior (anterior dislocation) or posterior (posterior dislocation) to the glenoid in relation to the 'Y'.
  • Evaluates for fractures of the scapular body and neck.
  • Should show no superimposition of the humeral head on the scapular body.

Axillary View (West Point, Neer, Velpeau)

• Patient Position & Part Position:
  • West Point/Neer (Standard Abduction): Patient seated or supine. Arm abducted 90 degrees, elbow flexed, hand positioned superiorly. Detector placed vertically against the superior aspect of the shoulder (West Point) or under the axilla (Neer).
  • Velpeau (Minimally Abducted/Immobilized): Patient standing, leaning posteriorly 30-45 degrees. Affected arm remains immobilized in a sling or by the side. Detector placed under the axilla or posterior to the shoulder.
• CR:
  • West Point: 25 degrees anteriorly and 25 degrees medially. Centered to the axilla.
  • Neer: 15 degrees inferiorly. Centered to the axilla.
  • Velpeau: 5-15 degrees cephalad. Centered to the mid-axilla.
• Key Anatomy: Glenoid, humeral head, coracoid, acromion, lesser tuberosity in profile. Demonstrates the critical relationship of the humeral head to the glenoid.
• Evaluation Criteria:
  • Essential for dislocations: Confirms anterior or posterior dislocation and may show superior/inferior displacement.
  • Identifies fractures of the glenoid rim (Bankart lesion) and humeral head compression fractures (Hill-Sachs lesion).
  • Velpeau view is invaluable for trauma when the patient cannot abduct their arm.

Specific Rotator Cuff Views

AP Internal Rotation

• Patient Position: Same as AP External Rotation.
• Part Position: Arm internally rotated, with the dorsal aspect of the hand on the hip. Epicondyles are perpendicular to the detector.
• CR: Perpendicular to the detector, directed to a point approximately 1 inch inferior to the coracoid process.
• Key Anatomy: The lesser tuberosity is seen in profile medially. Humeral head.
• Evaluation Criteria:
  • Primarily evaluates for fractures of the lesser tuberosity.
  • Can demonstrate calcific tendinitis within the subscapularis tendon.
  • Complements the AP External Rotation view for full humeral head assessment.

Supraspinatus Outlet (Neer Tangential / Y-view with Angle)

• Patient Position: Erect, patient rotated 45-60 degrees toward the affected side, similar to the Scapular Y view.
• Part Position: The scapula must be perpendicular to the detector.
• CR: 10-15 degrees caudal angle. Centered to the superior aspect of the humeral head.
• Key Anatomy: The acromial outlet is visualized tangentially, demonstrating the morphology of the acromion (e.g., Type I, II, III). The space between the humeral head and the acromion is evaluated.
• Evaluation Criteria:
  • Assesses acromial shape (flat, curved, hooked) which is highly relevant to impingement syndrome.
  • Identifies osteophytes or spurs that may narrow the supraspinatus outlet.
  • Evaluates for fractures of the acromion.

Garth View (AP Oblique for Hill-Sachs)

• Patient Position: Erect or supine, affected side rotated 45 degrees towards the detector.
• Part Position: Arm slightly abducted, hand pronated.
• CR: 45 degrees caudal angle. Centered to the scapulohumeral joint.
• Key Anatomy: Provides a profile view of the posterolateral aspect of the humeral head.
• Evaluation Criteria:
  • Specifically designed to demonstrate Hill-Sachs deformities (compression fracture of the posterolateral humeral head), which are commonly associated with anterior dislocations.
  • Can also provide an alternative view for glenoid rim fractures.

Stryker Notch View

• Patient Position: Supine. The affected arm is flexed at the elbow, with the hand resting on top of the head.
• Part Position: The palm of the affected hand rests on the top of the head.
• CR: 10 degrees cephalad angle. Centered to the coracoid process.
• Key Anatomy: Visualizes the posterosuperior aspect of the humeral head.
• Evaluation Criteria:
  • Excellent for visualizing Hill-Sachs lesions (often providing a clearer view than the Garth view in certain cases).
  • Requires patient cooperation and the ability to raise the arm.

Red Flags / Warnings

• Pain & Limited Motion: Always consider fracture or dislocation. Never force joint motion in a trauma setting.
• Neurovascular Compromise: Immediately check for signs of nerve or blood vessel damage (e.g., pallor, pulselessness, paresthesia, paralysis, decreased sensation over deltoid for axillary nerve). This is an emergent situation.
• Irreducible Dislocations: If a dislocation cannot be reduced easily, suspect intra-articular fragments, soft tissue interposition, or a locked dislocation.
• Pathological Fractures: If trauma seems minor for the injury observed, look for underlying bone lesions (e.g., lytic or blastic metastases, primary tumors).
• "Light Bulb Sign" on AP: Highly suggestive of a posterior shoulder dislocation, where the internally rotated humeral head appears rounded and fixed.
• "Rim Sign" on AP: Widening of the space between the anterior glenoid rim and the humeral head, suggestive of posterior dislocation.
• Hill-Sachs & Bankart Lesions: These findings are critical indicators of shoulder instability and often lead to recurrent dislocations.
• Missed Fractures: Fractures of the glenoid, coracoid, or lesser tuberosity can be subtle. Always review all three trauma views carefully and methodically.
• Younger vs. Older Patients: Young patients are more prone to dislocations, while older patients (especially with osteoporosis) are more likely to sustain proximal humerus fractures with similar mechanisms of injury.
• Inadequate Views: If an initial series is inconclusive or limited by patient pain, ensure alternative views (e.g., Velpeau axillary, transthoracic lateral) are performed before clearing for discharge.