CT Shoulder Without Contrast
Order a noncontrast CT of the shoulder to definitively characterize the fracture pattern and distinguish it from subcortical cystic changes. 1
Rationale for Noncontrast CT
CT is the best imaging modality for identifying and characterizing shoulder fracture patterns when radiographs are equivocal or show possible acute fracture. 1 The ACR Appropriateness Criteria explicitly state that CT provides superior delineation of:
- Fracture displacement and comminution 1
- Intra-articular extension 1
- Angulation patterns (AP and glenopolar) 1
- Lateral border offset 1
Three-dimensional volume-rendered CT images should be obtained to better visualize fracture displacement, angulation, and overall fracture geometry, which directly impacts surgical decision-making and functional outcomes. 1
Why Not Contrast-Enhanced CT
Intravenous contrast is not necessary for fracture characterization unless there is clinical concern for arterial injury, which is not indicated in your scenario. 1 Contrast would add unnecessary cost, time, and potential adverse effects without improving fracture visualization.
Distinguishing Fracture from Cystic Changes
The noncontrast CT will definitively differentiate between:
- Acute fracture: Shows cortical disruption, fracture lines, and potential displacement 1
- Subcortical cystic changes: Appear as well-defined lucencies without cortical interruption or acute fracture characteristics 2
Research demonstrates that subcortical cysts in bone are typically associated with adjacent soft tissue pathology (such as rotator cuff tears in the shoulder) and represent chronic degenerative changes rather than acute trauma. 2, 3 CT will clearly show whether cortical integrity is maintained (suggesting cystic change) or disrupted (confirming acute fracture).
Alternative Considerations
MRI without contrast could be considered if CT is contraindicated, though it is inferior to CT for fracture characterization. 1 MRI would be more useful if you suspect occult fracture with bone marrow edema or need to evaluate associated rotator cuff pathology, but CT remains superior for defining fracture lines and surgical planning. 1, 4
Avoid CT arthrography in this acute setting as intra-articular contrast can obscure fracture planes and is not indicated for fracture evaluation. 1