Is it likely a chest contusion after a minor car collision with a normal chest X-ray, no acute cardiopulmonary disease, and inflammation but no bruising, given the mechanism of injury and symptoms?

Chest Contusion After Minor Motor Vehicle Collision

Yes, it is entirely reasonable to diagnose a chest wall contusion in this patient given the mechanism of injury (seatbelt restraint during motor vehicle collision), visible inflammation, and clinical presentation, even with a normal chest X-ray and absence of bruising. 1

Clinical Reasoning

Why This Is Likely a Chest Wall Contusion

• Mechanism of injury strongly supports the diagnosis: Seatbelt restraint during motor vehicle collisions commonly causes chest wall contusions through compression forces between the seatbelt and chest wall, even in "minor" collisions 1, 2

• Normal chest X-ray does NOT exclude chest wall injury: Chest radiography is insensitive for soft tissue injuries and muscle contusions of the chest wall. The X-ray primarily rules out more serious injuries like rib fractures, pneumothorax, hemothorax, or acute cardiopulmonary disease 2, 3

• Visible inflammation without bruising is consistent: Chest wall contusions can present with localized inflammation, tenderness, and pain without visible ecchymosis, especially in the early hours after injury. Bruising may develop later or not at all depending on the depth and severity of tissue injury 2

• Activity restrictions are appropriate: The instruction to avoid lifting and strenuous exercise is standard management for chest wall contusions to prevent exacerbation of pain, allow tissue healing, and avoid complications 2

Important Clinical Considerations

Common pitfalls to avoid:

• Do not dismiss "minor" mechanisms of injury: Even low-energy trauma can produce significant injuries, particularly in patients over 55 years old. However, in this case with normal imaging and stable vital signs, serious injury is unlikely 4

• Cardiac contusion remains a consideration: While rare (5-50% incidence in blunt chest trauma), cardiac contusion can occur even without obvious external chest wall injury and may present with delayed symptoms 5, 6. The normal chest X-ray and absence of acute cardiopulmonary disease make this less likely, but the patient should be counseled to return if they develop:

  • Persistent or worsening chest pain
  • Shortness of breath
  • Palpitations or irregular heartbeat
  • Syncope or near-syncope 5, 6

• Myocardial infarction from coronary dissection is possible but rare: Blunt chest trauma can cause coronary artery dissection leading to myocardial infarction, though this typically presents with more severe symptoms 6

When Further Evaluation Would Be Indicated

The European Association of Cardiovascular Imaging guidelines specify that in patients with minor chest injuries and no tachycardia, hypotension, respiratory difficulty, chest pain, or other concerning symptoms, no intervention besides clinical assessment may be needed 1

Further cardiac evaluation (ECG, troponin, echocardiography) would be indicated if the patient develops: 1, 5

• Persistent tachycardia or hypotension
• Abnormal heart sounds or new murmur
• ECG abnormalities
• Persistent or progressive chest pain
• Signs of heart failure
• Arrhythmias

Management Summary

For this patient with isolated chest wall contusion:

• Pain control is paramount: Adequate analgesia prevents respiratory splinting and subsequent complications like atelectasis or pneumonia 2

• Activity modification: Avoid heavy lifting, pushing, pulling, and strenuous exercise for 2-4 weeks or until pain resolves 2

• Return precautions: Instruct the patient to seek immediate evaluation for worsening chest pain, shortness of breath, palpitations, or syncope 5, 6

• Follow-up: Routine follow-up in 1-2 weeks to ensure symptom resolution is reasonable, though not always necessary for simple contusions 2

The diagnosis of chest wall contusion is appropriate and the management plan described is consistent with standard trauma care guidelines 1, 2