Learning Radiology xray montage

Flail Chest

General Considerations

  • Segment of thoracic cage is separated from remainder of chest wall by significant blunt chest trauma
  • Relatively uncommon, but potentially life-threatening
  • Definition varies from two fractures per rib for two contiguous ribs to two fractures per rib for three contiguous ribs
  • Sternum may also be involved with ribs on both sides of chest
  • Severity of underlying lung and cardiac injury are clinically more important than fractures themselves

Clinical Findings

  • Chest wall bruising
  • Pain on inspiration
  • Crepitus
  • Flail segment moves paradoxically with respiration
    • Moves inward on inspiration and outward on expiration

Imaging Findings

  • Chest radiographs are invariably performed first
    • Two or more fractures in two or three or more contiguous ribs
    • Chest x-rays tend to underestimate the number of fractures
  • Chest CT is also invariably performed, and may show
    • Rib fractures
    • Pulmonary contusion (almost always)
      • Airspace disease representing hemorrhage into the alveoli usually subjacent to the point of impact
    • Pulmonary laceration
      • Lacerations in the lung may be blood-containing, air-containing, or both
      • Frequently masked by the surrounding pulmonary contusion
    • Pneumothorax (very common)
      • Since the severity of the injury means a supine radiograph will be performed, pneumothoraces may only be seen on chest CT
    • Hemothorax (common)
    • Pneumomediastinum
    • Subcutaneous emphysema
    • Mediastinal hemorrhage
    • Aortic injuries


  • Analgesia, including intercostal nerve blocks
  • Ventilation and oxygenation
    • Patients who do not need mechanical ventilation do better than those who do


  • Almost always accompanied by pulmonary contusion
  • May have long-term disability
    • Chest wall pain
    • Respiratory distress


  • Up to 10% mortality if patients reach hospital alive

Flail Chest. Radiograph demonstrates multiple rib fractures (black arrows) with
some ribs fractured in two or more places. There is also a pulmonary contusion (red arrow) and subcutaneous emphysema (white arrow)
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eMedicine: Flail Chest. Bjerke, H