Plain X-ray of the Right Shoulder
Start with plain radiography of the shoulder, then proceed to MRI without contrast or ultrasound to confirm the clinically evident biceps tendon rupture and evaluate for associated rotator cuff pathology.
Clinical Presentation Analysis
This patient has a classic presentation of a proximal long head of biceps tendon rupture:
- Acute onset with audible "pop" during heavy lifting
- Anterior upper arm swelling and deformity (likely "Popeye sign")
- Positive Speed and Yergason tests
- Point tenderness over anterior upper arm
While the clinical diagnosis is relatively straightforward, imaging is essential to rule out associated injuries and guide management decisions that affect long-term function.
Imaging Algorithm
Step 1: Plain Radiography First
Radiography is the mandatory initial study for all acute shoulder pain 1, 2. This is non-negotiable regardless of how obvious the clinical diagnosis appears. The ACR Appropriateness Criteria (2025) explicitly states radiography is "usually appropriate as the initial imaging study in the setting of acute shoulder pain of any etiology" 1.
Why radiographs matter here:
- Rule out proximal humerus fracture (can occur with same mechanism)
- Exclude glenohumeral dislocation
- Identify any bony avulsion at biceps origin
- Establish baseline for medicolegal documentation
Standard views should include anteroposterior (internal and external rotation) and axillary or scapula-Y views 2.
Step 2: MRI Without Contrast OR Ultrasound
After negative or non-specific radiographs, both MRI without contrast and ultrasound are "usually appropriate" and considered equivalent alternatives for suspected rotator cuff pathology 1. The 2025 ACR guidelines specifically state these are "equivalent alternatives and only one study needs to be ordered" 1.
Choose MRI without contrast if:
- Large body habitus limits ultrasound visualization
- Restricted range of motion due to acute pain
- Suspicion of additional intra-articular pathology (labral tears, rotator cuff tears)
- Need comprehensive evaluation of all soft tissues
Choose ultrasound if:
- Experienced musculoskeletal sonographer available
- Patient has MRI contraindications
- Cost is a significant concern
- Focused evaluation of biceps and rotator cuff is sufficient
Why This Matters for Outcomes
The biceps tendon rupture itself rarely requires surgical repair in a 44-year-old, but associated rotator cuff tears occur in up to 50% of cases and significantly impact functional outcomes 3. Missing a concomitant rotator cuff tear leads to:
- Persistent pain and weakness
- Progressive functional decline
- Delayed appropriate surgical intervention if needed
MRI is superior to ultrasound for detecting partial-thickness rotator cuff tears and intra-articular pathology 2, which is why it may be preferred in this acute traumatic setting despite the guidelines listing them as equivalent 1.
Common Pitfalls to Avoid
- Don't skip radiographs: Even with obvious clinical findings, fractures and dislocations must be excluded
- Don't order MR arthrography acutely: The acute hemarthrosis/effusion provides natural contrast; arthrography is unnecessary and adds risk 1
- Don't assume the "pop" confirms acute pathology: Recent evidence shows "feeling a pop" has limited diagnostic value for acute tendon rupture 4, though the combination with deformity is more specific
- Don't order arthroscopy as a diagnostic test: This is therapeutic, not diagnostic imaging
Bottom Line
Plain radiographs first (mandatory), followed by either MRI without contrast (preferred for comprehensive evaluation) or ultrasound (acceptable if expertise available) to confirm biceps rupture and critically evaluate for rotator cuff tears that will determine surgical candidacy and long-term shoulder function 1, 2.