What is the appropriate diagnostic imaging for a suspected humerus injury?

Appropriate Diagnostic Imaging for Suspected Humerus Injury

Standard radiography with multiple views is the appropriate initial diagnostic imaging for suspected humerus injuries, with CT being the next appropriate study for complex fracture characterization when radiographs are indeterminate or inadequate.

Initial Imaging Approach

Standard Radiographs (First-Line)

• For suspected humerus injuries, plain radiographs should include at minimum:

  • Anteroposterior (AP) views in internal and external rotation
  • Axillary or scapular Y-view (critical for proper alignment assessment)
  • Additional views may include Stryker notch view for Hill-Sachs lesions 1

• Radiographs provide excellent delineation of:

  • Fracture presence and pattern
  • Appropriate shoulder alignment
  • Aid in fracture classification
  • Help determine appropriate management approach (surgical vs. nonsurgical) 1

Benefits of Standard Radiographs

• Cost-effective initial screening
• Widely available
• Provide sufficient information for many uncomplicated fractures
• Can confirm successful glenohumeral joint reduction following dislocation 1

Limitations of Standard Radiographs

• May miss subtle nondisplaced fractures
• Limited in evaluating complex fracture morphology
• Poor inter-observer reliability in grading humeral fractures 1
• Scapular Y-views show significantly more overlap of fractured regions (mean 71.5%) compared to axillary views (mean 56.2%) 2

Second-Line Imaging

CT Without IV Contrast

• Indicated when:

  • Radiographs are indeterminate or inadequate
  • Complex comminuted fractures are present
  • Subtle nondisplaced fractures are suspected
  • Detailed fracture characterization is needed for surgical planning 1

• CT is advantageous over radiography in:

  • Identifying subtle nondisplaced fractures
  • Characterizing fracture morphology in complex cases
  • Affecting clinical management in up to 41% of proximal humeral fractures 1
  • Providing 3D reconstruction for better visualization of fracture patterns 1

MRI Without IV Contrast

• Indicated when:

  • Soft tissue injury evaluation is needed alongside bone assessment
  • Radiographs are normal but clinical suspicion remains high
  • Bone marrow contusion is suspected
  • Pediatric physeal injuries are suspected 1

• MRI benefits include:

  • Evaluation of associated soft tissue injuries (rotator cuff tears, capsular/ligament tears)
  • Assessment of bone marrow contusion
  • Detection of occult fractures not visible on radiographs 1

Special Considerations

Pediatric Patients

• MRI is beneficial in assessing shoulder physeal injuries in children 1
• Can distinguish potentially unstable fractures from minimally displaced ones in lateral humeral condyle fractures 3

Complex Proximal Humeral Fractures

• CT provides clinically useful information when radiographs are inadequate
• Can prevent unnecessary surgery by showing no significant displacement in fragments previously judged as displaced on radiographs 4
• Can reveal unsuspected abnormalities that direct surgical approach 4

Imaging Quality Considerations

• High-quality axillary views are superior to scapular Y-views for fracture assessment 5, 2
• Internal oblique radiographs are valuable for pediatric lateral condylar fractures, showing more accurate displacement in 70% of cases 6

Common Pitfalls to Avoid

1. Relying solely on AP views: Axillary or scapular Y-views are vital as acromioclavicular and glenohumeral joint dislocations can be misclassified on AP views alone 1

2. Underestimating fracture complexity: CT should be performed when radiographs don't provide sufficient quality to establish a treatment plan, regardless of the number of fractured parts 2

3. Overlooking soft tissue injuries: Up to 40% of humeral head fractures have associated rotator cuff tears 1

4. Inadequate views for pediatric fractures: Consider additional internal oblique views for pediatric lateral condylar fractures 6