Is a shoulder anteroposterior (AP) and posteroanterior (PA) view sufficient to diagnose any issues?

Shoulder AP and PA Views Are Insufficient for Trauma Evaluation

No, shoulder AP (anteroposterior) views alone—whether in internal/external rotation or with a PA view—are inadequate for comprehensive shoulder trauma assessment; you must obtain at least three views including an orthogonal view (axillary or scapula-Y) to avoid missing critical injuries, particularly dislocations. 1

Why AP Views Alone Are Inadequate

The critical limitation: Glenohumeral and acromioclavicular dislocations are frequently misclassified or completely missed on AP views alone, with posterior dislocations missed in over 60% of cases when orthogonal views are not obtained. 1, 2

• AP views detect approximately 88% of shoulder injuries, but this leaves a significant 12% of pathology undiagnosed without additional projections 3
• Specific injuries that AP views commonly miss include:
  • Posterior glenohumeral dislocations (the most critical miss) 2
  • Glenohumeral joint alignment abnormalities 1
  • Scapular body and coracoid process fractures 3
  • Subtle glenoid rim fractures 2

The Minimum Required Standard

Standard trauma shoulder radiography must include at minimum three views: 1

1. AP view in internal rotation 1
2. AP view in external rotation 1
3. Axillary OR scapula-Y view (orthogonal to the AP plane) 1

Why the Third View Is Non-Negotiable

The axillary or scapula-Y view is vital because it provides the orthogonal plane necessary to:

• Confirm or exclude glenohumeral dislocation (anterior vs. posterior) 1, 2
• Assess true shoulder alignment 1
• Identify Hill-Sachs lesions (posterolateral humeral head compression fractures) 2
• Detect bony Bankart lesions (anterior glenoid rim fractures) 2

Clinical pitfall: Attempting reduction of a suspected dislocation without confirming the diagnosis and direction with proper radiographic views could worsen fracture-dislocations and cause neurovascular injury. 2

Comparative Value of Different Views

Research directly comparing projection effectiveness shows: 3, 4

• AP views: Most sensitive overall (88% detection rate), best for most fractures 3
• Axillary/oblique views: Essential for dislocations and specific fracture patterns (82% detection rate for oblique apical) 3
• Combined approach: The orthogonal views detect injuries missed by AP alone in approximately 4-15% of cases 3, 5

When to Add Additional Views

Consider supplementary projections based on clinical suspicion: 1

• Stryker notch view: For suspected Hill-Sachs lesions 1
• Bernageau view: To assess degree of glenoid or humeral head bone loss 1
• Transthoracic lateral: If axillary view cannot be obtained due to pain, though this is less ideal 5

Advanced Imaging Indications

If radiographs are normal or indeterminate but clinical suspicion remains high: 1

• CT without contrast: Superior for characterizing fracture patterns, detecting subtle nondisplaced fractures, and identifying scapular fractures; changes management in up to 41% of proximal humeral fractures 1
• MRI without contrast: Effective for soft-tissue pathology (rotator cuff tears, labral injuries) and can also assess bony morphology and bone loss 1
• Ultrasound: Limited utility in acute trauma unless rotator cuff or biceps tendon injury is specifically suspected; poor for bone evaluation 1

Common pitfall: Radiographs should be performed upright when possible, as supine positioning can underrepresent shoulder malalignment. 1