What is the most appropriate next step in management for a patient with suspected rotator cuff injury after a fall, with pain over the deltoid region and positive exam findings, but negative x-rays?

MRI Shoulder Without IV Contrast

For this 36-year-old patient with suspected rotator cuff tear following trauma, positive physical examination findings (positive empty can and drop arm tests), and negative x-rays, the most appropriate next step is MRI shoulder without IV contrast. 1

Rationale for MRI Without Contrast

MRI shoulder without IV contrast is the optimal imaging modality for evaluating suspected rotator cuff tears in the acute post-traumatic setting. 1 The American College of Radiology 2025 guidelines specifically state that MRI without IV contrast is "generally considered the best modality for adequately assessing most soft tissue injuries, including labroligamentous, cartilage, and rotator cuff pathology, particularly in the setting of recent trauma." 1

Diagnostic Performance

• MRI demonstrates 98% sensitivity and 79% specificity for detecting any rotator cuff tears, and 94% sensitivity and 93% specificity specifically for full-thickness tears. 2, 3

• For full-thickness tears (which this patient likely has given the positive drop arm test), MRI achieves summary sensitivity of 94% and specificity of 93%. 3

• The presence of post-traumatic joint effusion in acute trauma actually enhances soft tissue visualization on non-contrast MRI, making it preferable to MR arthrography in this acute setting. 1

Why Not Other Imaging Modalities?

Ultrasound Limitations

While ultrasound has comparable performance to MRI for full-thickness tears (92% sensitivity, 93% specificity), it has significant limitations in this case: 1, 3

• Variable interobserver agreement for partial-thickness tears makes ultrasound less reliable. 1, 2
• Ultrasound performance is highly operator-dependent and may be limited by acute pain restricting range of motion. 1
• MRI is preferred when there is suspicion of other intra-articular pathologies (labral tears, cartilage injury) that may coexist with rotator cuff pathology. 1

MR Arthrography Not Indicated

• MR arthrography is reserved for detecting partial-thickness tears when conventional MRI is equivocal, not as the initial study. 1
• In acute trauma with post-traumatic effusion present, the joint is already distended, negating the advantage of arthrography. 1

CT Has No Role

• Non-contrast CT cannot assess rotator cuff pathology in the acute setting and should not be used for soft-tissue evaluation. 1, 2

Clinical Context Supporting Full-Thickness Tear

This patient's presentation strongly suggests a full-thickness rotator cuff tear based on: 4

• Positive drop arm test (highly specific for full-thickness tears)
• Positive empty can test (supraspinatus involvement)
• Weakness with external rotation (infraspinatus/teres minor involvement)
• Weakness with internal rotation (subscapularis involvement)
• Severe night pain (characteristic of full-thickness tears)
• Traumatic mechanism (fall on outstretched arm)

Management Implications

The MRI findings will guide treatment decisions: 2, 5

• Most rotator cuff injuries can initially be managed conservatively with NSAIDs, corticosteroid injections, and functional rehabilitation. 5, 6
• MRI will assess tear size, tendon retraction, muscle atrophy, and fatty infiltration—all critical factors determining whether conservative versus surgical management is appropriate. 1
• Delayed rotator cuff repair up to 4 months has not shown adverse outcomes, allowing time for conservative management trial. 2

Critical Pitfall to Avoid

Do not proceed directly to orthopedic referral without advanced imaging. While the clinical examination is highly suggestive, MRI is essential to confirm the diagnosis, characterize tear extent and quality of remaining tendon, and guide appropriate treatment planning—whether conservative management or surgical repair. 1, 2