What is the best way to order a chest x-ray to diagnose a broken rib?

Ordering Chest X-Ray for Suspected Rib Fracture

Order a standard posteroanterior (PA) chest radiograph as the initial imaging study for suspected rib fractures, but understand that detecting the fracture itself is often less important than identifying life-threatening complications like pneumothorax or hemothorax. 1, 2

Initial Imaging Approach

A standard PA chest X-ray should be your first-line imaging modality for suspected rib fractures, despite missing up to 50% of actual fractures. 2 The primary value of the chest X-ray is not fracture detection per se, but rather identifying complications that significantly impact morbidity and mortality—such as pneumothorax, hemothorax, flail chest, or pulmonary contusion. 1, 2

Key Points About Standard Chest X-Ray:

• Do NOT order dedicated "rib series" or rib detail views as they rarely change management (only 0.23% of cases) and actually delay care by prolonging report turnaround time. 1
• Multiple studies confirm that rib series detect more fractures than PA views alone, but this increased detection does not translate to different treatment decisions. 1
• The chest X-ray's real clinical value lies in detecting organ injuries and complications, not counting every fracture. 2

When to Escalate to CT Chest

Consider CT chest (without IV contrast initially) in specific high-risk scenarios where fracture burden and complications directly affect mortality and morbidity:

High-Energy Trauma or Multiple Injuries:

• Order CT when there is high clinical suspicion of intrathoracic or intra-abdominal injury, particularly with high-energy mechanisms. 1
• Rib fractures detected on chest X-ray that show underlying parenchymal abnormality are associated with 3.8 times higher pulmonary morbidity compared to CT-only detected fractures. 1
• This suggests that fractures visible on X-ray with associated lung injury warrant closer monitoring, while CT-only fractures may be clinically insignificant. 1

Elderly Patients (≥65 years):

• Lower threshold for CT in elderly patients, as increased rib fracture burden directly correlates with higher morbidity and mortality in this population due to poor cardiopulmonary reserve. 1
• The number of fractures and degree of displacement predict pulmonary complications including pneumonia, atelectasis, and respiratory failure. 1

Severe Injury Indicators:

• Consider CT when clinical findings suggest severe injury: flail chest, suspected first rib fracture, lower rib fractures (ribs 7-12) with abdominal tenderness, or bilateral fractures. 1
• Lower rib fractures in patients with multiple injuries are associated with abdominal organ injury in 67% of cases. 1

Pathologic Fracture Suspected:

• Order CT chest without IV contrast when spontaneous or minimal-trauma fractures suggest underlying malignancy or metabolic bone disease. 1, 2

What NOT to Do

Common Pitfalls:

• Avoid ordering rib series routinely—they prolong care without changing management in 99.77% of cases. 1
• Do not order CT for simple, isolated rib fractures from low-energy trauma with normal vital signs and no evidence of complications. 1
• In low-energy trauma with normal physical examination, neither rib series nor chest X-rays may be clinically beneficial. 1

Alternative Imaging Considerations

Ultrasound:

• Point-of-care ultrasound is more sensitive than chest X-ray (100% vs 40% sensitivity in one study) and may be considered when available and operator expertise exists. 3
• Ultrasound is particularly useful for costochondral junction injuries not visible on X-ray. 2
• However, ultrasound commonly misses upper rib fractures and lacks guideline support as a primary modality. 3

Bone Scan:

• Tc-99m bone scan may be complementary when pathologic fracture is suspected but has limited utility in distinguishing acute from chronic fractures (can remain positive for up to 3 years). 1, 2

Clinical Decision Algorithm

1. Start with PA chest X-ray for all suspected rib fractures 1, 2
2. Assess for complications on X-ray (pneumothorax, hemothorax, pulmonary contusion) 1, 2
3. If low-energy trauma + normal exam + no X-ray complications → Symptomatic treatment, no further imaging 1
4. If high-energy trauma OR elderly (≥65) OR multiple injuries OR lower rib fractures with abdominal findings → Order CT chest 1
5. If spontaneous/minimal trauma fracture → Consider CT to evaluate for pathologic process 1, 2

The critical insight is that detecting every rib fracture is less important than identifying complications that affect mortality and quality of life—this should guide your imaging decisions. 2