X-ray is the Most Appropriate Next Step
For a patient presenting with acute shoulder injury, inability to raise the arm, and visible deformity, plain radiography is the mandatory first imaging study to confirm the diagnosis, identify fractures, and guide immediate management. 1
Initial Imaging Approach
- Standard shoulder radiographs should include anteroposterior (AP) views in internal and external rotation PLUS an axillary or scapular Y view to properly evaluate for dislocation and associated fractures 2, 1
- The axillary or scapular Y view is critical because AP views alone miss up to 60% of dislocations, particularly posterior dislocations 1
- Radiography must be performed BEFORE attempting any reduction to avoid worsening occult fracture-dislocations 1
Why X-ray First (Not MRI or CT)
The visible deformity and inability to raise the arm strongly suggest either:
- Glenohumeral dislocation (most commonly anterior)
- Proximal humerus fracture
- Clavicle fracture
- Acromioclavicular separation
Plain radiographs are sufficient to diagnose these conditions and guide immediate treatment 2, 1. Advanced imaging comes later, not now.
When Advanced Imaging Becomes Appropriate
After Initial Radiographs Are Obtained:
- MRI without contrast is indicated if radiographs show dislocation and you need to assess soft tissue injuries (rotator cuff tears, labral injuries, capsular tears) in the acute setting, as the traumatic joint effusion acts as natural contrast 2
- CT without contrast is reserved for better characterizing complex fracture patterns (especially scapular or proximal humerus fractures) when surgical planning is needed 2
- MRI is particularly important in older patients with dislocation, as rotator cuff tears are commonly associated 1
Critical Pitfalls to Avoid
- Never attempt reduction without radiographic confirmation - you could convert a simple dislocation into a fracture-dislocation 1
- Never rely on AP views alone - obtain the axillary or scapular Y view to avoid missing the diagnosis 2, 1
- Assess neurovascular status immediately and obtain CT angiography if vascular compromise is suspected, especially with proximal humerus fractures where axillary artery injury can occur 1
- Delaying reduction after radiographic confirmation increases risk of neurovascular complications 1
Answer: C - X-ray
The clinical presentation demands immediate plain radiography with proper orthogonal views before any other intervention or advanced imaging.