Is an anterior-posterior (AP) view chest X-ray sufficient to rule out a compression fracture?

Anterior-Posterior View Chest X-ray Is Insufficient to Rule Out Compression Fracture

An anterior-posterior (AP) view chest X-ray alone is insufficient to rule out a compression fracture and should be supplemented with additional imaging when compression fracture is clinically suspected. 1

Limitations of AP Chest X-ray for Compression Fracture Detection

AP chest X-rays have significant limitations for detecting compression fractures:

• Standard chest radiography detects only about 60% of fractures that are identified by CT 1
• Anterior and posterior fractures are particularly difficult to visualize on AP views alone 1
• Compression fractures of the spine may be completely missed or underdiagnosed on standard chest radiographs 2

Appropriate Imaging Algorithm for Suspected Compression Fracture

Initial Imaging

1. For suspected rib fractures:

   • Standard chest radiograph with posteroanterior (PA) and lateral views 2
   • Additional dedicated rib views may not change management outcomes despite detecting more fractures 1

2. For suspected vertebral compression fractures:

   • Initial evaluation with radiography including anteroposterior and lateral views of the spine 1
   • Upright radiographs provide functional information about axial loading 1

When to Pursue Advanced Imaging

Advanced imaging is indicated in the following scenarios:

• CT is indicated when:

  • There is high clinical suspicion with negative initial X-ray 2
  • Multiple trauma with suspected additional injuries 2
  • Precise fracture characterization would change management 2
  • First rib fracture is suspected (due to risk of vascular injury) 2

• MRI is indicated when:

  • Determining acuity of vertebral fracture is necessary 1
  • Bone marrow edema assessment is needed 1
  • Spinal canal compromise is suspected 1
  • Distinguishing between malignant and benign compression fractures 1, 3

Clinical Significance and Implications

Missing compression fractures has significant clinical implications:

• Vertebral compression fractures are the most common complication of osteoporosis, with 700,000 cases annually in the US 3
• Undiagnosed vertebral fractures on chest CT are associated with triple the risk of future hip fractures (HR = 3.1) 4
• Risk increases with fracture severity: mild (HR = 2.4), moderate (HR = 4.8), severe (HR = 6.7) 4
• Patients with compression fractures may benefit from interventions like kyphoplasty or vertebroplasty for symptom relief 3

Common Pitfalls in Compression Fracture Imaging

• Over-reliance on AP views alone without lateral projections
• Failure to obtain additional imaging when clinical suspicion is high despite negative initial X-rays
• Not considering CT for complex fracture patterns or when complications are suspected
• Overlooking the need for MRI to determine fracture acuity, which affects treatment decisions 3
• Missing the association between rib fractures and underlying vertebral injuries

In summary, while an AP chest X-ray is often the initial imaging study performed, it should not be considered sufficient to rule out compression fractures. A more comprehensive imaging approach is necessary when compression fractures are clinically suspected.