When is a hand x-ray (radiograph) indicated?

When is a Hand X-ray Indicated?

Hand radiographs are usually appropriate as the initial imaging study for any adult presenting with acute blunt or penetrating trauma to the hand, and should be obtained whenever there is clinical suspicion of fracture (indicated by swelling, bruising, or deformity). 1, 2

Primary Indications for Hand X-ray

Acute Trauma Settings

• Blunt or penetrating hand trauma is the most common indication, where radiographs serve as the first-line imaging modality 1
• Clinical signs requiring imaging include swelling, bruising, deformity, or point tenderness over bony structures 3
• Suspected fractures or dislocations of the metacarpals, phalanges, or interphalangeal joints warrant immediate radiographic evaluation 2

Non-Traumatic Indications

• Suspected rheumatoid arthritis or inflammatory arthropathy, where hand x-rays identify erosions, joint space narrowing, and deformities that are diagnostic and track disease progression 4
• Hand osteoarthritis evaluation, as radiographic findings correlate highly with histopathological changes (correlation coefficient 0.79-0.87) and support diagnosis even without clinical bony swelling 5
• Foreign body detection following penetrating injury, particularly for radiopaque materials 1

Essential Technical Requirements

Standard Radiographic Protocol

• A minimum 3-view examination is mandatory for adequate evaluation, including posteroanterior (PA), lateral, and oblique views 2, 3
• Two views are inadequate and lead to missed fractures, particularly in phalangeal injuries where the oblique view is absent in 64% of cases in some series 3
• An internally rotated oblique projection in addition to the standard externally rotated oblique increases diagnostic yield for phalangeal fractures 2

Common Pitfalls to Avoid

• Relying on only 2 views is the most common error, with studies showing less than half of hand fracture patients receive appropriate 3-view imaging 3
• Inadequate views for specific injuries: 38% of metacarpal fractures lack lateral views, and 64% of phalangeal fractures lack oblique views 3
• Failure to obtain dedicated finger views: While some centers image the entire hand, others appropriately limit examination to the injured finger for phalangeal injuries 2

When Initial Radiographs Are Negative or Equivocal

Next Steps Algorithm

If clinical suspicion remains high despite negative initial radiographs, the American College of Radiology recommends three equivalent options 1:

1. Repeat radiographs in 10-14 days after short arm cast immobilization 2
2. MRI without IV contrast to detect occult fractures 2
3. CT without IV contrast for equivocal findings 1

Advanced Imaging Considerations

• MRI or ultrasound is appropriate when radiographs show acute hand fracture but suspected tendon or ligament trauma requires evaluation 1
• MRI or ultrasound is also appropriate for joint malalignment (MCP, PIP, or DIP) without visible fracture 1
• CT is usually not indicated for metacarpal and digital fractures during acute injury unless there is deep tissue or bone penetration by foreign body 2, 1

Special Circumstances

Foreign Body Evaluation

• Initial radiographs detect radiopaque foreign bodies but may miss radiolucent materials 1
• If initial radiographs are negative, ultrasound or CT without IV contrast are equivalent appropriate next steps for suspected foreign bodies 1

Radiation Considerations

• Radiation exposure is minimal with hand radiographs, but the relative radiation level should be considered, particularly in pediatric patients who have inherently higher risk from exposure 1