What is the workup for a suspected torn bicep?

Workup for Suspected Torn Biceps Tendon

MRI is the most accurate imaging modality for diagnosing biceps tendon tears and should be the primary diagnostic tool after initial radiographs, as it correctly identifies the type of tear and enables precise treatment planning. 1

Initial Clinical Assessment

• Obtain history of mechanism of injury - eccentric extension load to the elbow is typical for distal biceps tears, while proximal tears often present with anterior shoulder pain 2, 3
• Look for key physical findings:
  • Acute antecubital pain and tenderness 4
  • Weakness of elbow flexion and forearm supination 4
  • Palpable defect in the antecubital region (complete tears) 2
  • "Reverse Popeye" deformity (may be present in partial tears) 5
• Perform specific diagnostic tests:
  • Biceps squeeze test 2
  • Hook test 2, 6
  • TILT sign 6
  • Biceps provocation test 6

Imaging Algorithm

1. Plain radiographs should be the first imaging study to rule out associated fractures or other bony abnormalities 1

2. MRI without contrast is the next appropriate imaging study:

   • MRI has superior accuracy (86.4%) compared to ultrasound (45.5%) for complete distal biceps tears 1
   • MRI demonstrates better sensitivity (76%) and specificity (50%) than ultrasound for biceps tendon tears 1
   • For optimal visualization, consider the FABS (flexion-abduction-supination) view - patient positioned with elbow flexed at 90°, shoulder abducted, and forearm supinated 1, 6

3. Ultrasound can be considered as an alternative when MRI is contraindicated:

   • While some studies show a slight statistical advantage of ultrasound over MRI 1, most evidence indicates ultrasound is inferior for complete tears (45.5% vs 86.4% accuracy) 1
   • Ultrasound has similar accuracy to MRI for partial tears (66.7%) 1
   • Ultrasound is particularly disadvantaged in detecting partial tearing and tendinopathy 1
   • If using ultrasound, the medial imaging approach is preferred by radiologists and shows substantial interreader agreement 1

Tear Classification and Management Considerations

• Determine tear location:

  • Proximal (long head) tears are more common and may be treated conservatively 3
  • Distal tears (3% of all biceps tendon ruptures) typically require surgical intervention 2

• Assess tear extent:

  • Partial tears <50% may be treated with nonoperative management or surgical debridement 4, 6
  • Partial tears >50% typically require surgical repair 4, 6
  • Complete tears generally benefit from early anatomic reattachment 2

• Consider tear chronicity:

  • Acute tears are easier to repair directly 2
  • Chronic tears may require tendon grafts due to retraction and poor tissue quality 2

Common Pitfalls to Avoid

• Failing to distinguish between partial and complete tears - MRI is crucial for this differentiation 1
• Missing associated injuries - biceps tears are often associated with rotator cuff pathology or ligamentous injuries 3
• Overlooking bifurcated distal biceps anatomy - selective disruption of short or long head components requires careful assessment 5
• Relying solely on ultrasound for diagnosis - while convenient, it has limitations in accuracy compared to MRI 1
• Delaying treatment of complete distal tears - early anatomic reattachment provides better outcomes 2