What are the key steps to diagnose a shoulder fracture in patients with shoulder pain, limited mobility, and swelling, especially after trauma?

Identifying a Shoulder Fracture

Begin with standard three-view radiography performed upright, which is the definitive initial diagnostic test for shoulder fractures and can identify most displaced fractures and shoulder malalignment. 1, 2

Initial Imaging Approach

Standard radiography must include at least three specific views:

• Anteroposterior (AP) views in both internal and external rotation 1, 2
• Axillary or scapula-Y view (critical to avoid missing dislocations that can be misclassified on AP views alone) 1, 2
• All views should be performed with the patient upright, as supine positioning can underrepresent shoulder malalignment 1

The axillary or scapula-Y view is vital because acromioclavicular and glenohumeral dislocations can be completely missed or misclassified if only AP views are obtained. 1

Clinical Presentation Indicators

Key clinical findings suggesting fracture include:

• History of trauma (high-energy in young patients, low-energy falls in older patients) 3
• Shoulder pain with limited mobility and swelling 3
• Patients holding the affected arm in their contralateral hand with pain on motion 3
• Palpable humeral head in the axilla or dimple inferior to the acromion (suggests dislocation with possible fracture) 3
• Inability to hold the affected arm in an elevated position 3

When Initial Radiographs Are Inadequate

If radiographs show a fracture but characterization is needed:

• CT without contrast is the gold standard for identifying and characterizing fracture patterns, particularly for complex proximal humerus fractures and scapula fractures 1
• CT demonstrates superior ability to assess fracture displacement, angulation, and intra-articular extension compared to radiography 1
• Three-dimensional CT reformations can better visualize fracture displacement and angulation 1

If radiographs are negative but clinical suspicion remains high:

• MRI without contrast has sensitivity and specificity comparable to bone scintigraphy for occult fractures 1
• MRI is equivalent to CT in identifying nondisplaced fractures that are typically missed on conventional radiography 1
• Bone scintigraphy can also identify occult fractures with comparable accuracy to MRI 1

Critical Pitfalls to Avoid

Common diagnostic errors include:

• Failing to obtain orthogonal views (axillary or scapula-Y), leading to missed fracture components or misclassification of dislocations 1, 2
• Performing radiographs with the patient supine rather than upright, which underrepresents malalignment 1
• Underestimating injury severity due to inadequate imaging, particularly with scapula fractures where complex anatomy and overlying ribs obscure fracture lines 1

Immediate Referral Indications

Refer immediately to orthopedic surgery for:

• Unstable or significantly displaced fractures 1, 2
• Presence of neurological deficits 2
• Shoulder joint instability 1, 2

Delaying surgical referral when indicated makes stabilization more technically challenging and can worsen outcomes. 2

Specific Fracture Types

Proximal humerus fractures:

• CT is preferred for characterizing complex fracture patterns, as poor inter-observer agreement exists when grading these fractures on radiography alone 1
• Up to 40% have associated rotator cuff tears, though immediate soft-tissue diagnosis may not be required as tears are typically addressed during fracture fixation 1

Scapula fractures:

• Easily missed or underappreciated on conventional radiography due to complex anatomy and overlying ribs 1
• CT is the best modality for identifying intra-articular extension, glenopolar angulation, and lateral border offset 1

Clavicle fractures:

• Standard radiography is typically sufficient for diagnosis 2
• Most nondisplaced or minimally displaced injuries can be treated conservatively with pain management, short-term sling use, and physical therapy 3