When is an X-ray (XR) recommended for arm pain?

X-ray Recommendations for Arm Pain

X-ray imaging is recommended as the initial imaging modality for all patients with acute arm pain following trauma, with specific views required depending on the suspected injury location (wrist, hand, elbow, or forearm). 1

Initial Radiographic Evaluation

• For wrist injuries, a standard 3-view radiographic examination is required, including posteroanterior (PA), lateral, and 45° semipronated oblique views 1
• For hand and finger injuries, a standard 3-view radiographic examination is necessary, including PA, lateral, and oblique views 1, 2
• For elbow or forearm pain, radiography is the appropriate initial imaging modality 1
• Two-view radiographic examinations are inadequate for detecting fractures in the extremities, especially those involving the wrist, hand, and fingers 1, 2

Specific Indications for X-ray in Arm Pain

• Suspected fracture following trauma 1
• Persistent pain after injury 1
• Point tenderness over a bone 1
• Visible deformity 1
• Limited range of motion 1
• Suspected dislocation 1
• Suspected foreign body 3

Special Considerations by Location

Wrist

• A fourth projection (semisupinated oblique) may increase diagnostic yield for distal radius fractures 1
• X-rays are particularly important for detecting intra-articular fractures that may require surgical intervention 4
• Sensitivity of X-ray compared to CT is highest for radius fractures (95%) but much lower for carpal bones 5

Hand/Fingers

• For phalangeal injuries, some centers include a PA examination of the entire hand, while others limit to the injured finger 1, 2
• An internally rotated oblique projection increases diagnostic yield for phalangeal fractures 1, 2
• Most thumb fractures are visible on a 2-view examination, though adding an oblique projection slightly increases diagnostic yield 1

Elbow/Forearm

• Radiography is the appropriate initial imaging for acute elbow or forearm pain 1
• X-rays can identify posterior and anterior fat pad elevation, suggesting joint effusion which may imply an occult elbow fracture 1

When Initial X-rays Are Negative or Equivocal

• In patients with high clinical suspicion but negative initial X-rays, options include:

  • Placing the patient in a short arm cast and repeating X-rays in 10-14 days 1
  • CT without IV contrast for suspected wrist fractures 1
  • MRI without IV contrast for suspected soft tissue injuries 1

• For suspected fracture with normal or indeterminate radiographs:

  • CT without IV contrast is appropriate for suspected bone injury 1
  • MRI without IV contrast is appropriate for suspected tendon, ligament, or muscle injury 1

Common Pitfalls to Avoid

• Relying on only 2 views is inadequate for detecting fractures in the extremities 1, 2
• Failure to obtain adequate radiographic views may lead to missed diagnosis, especially for carpal bone fractures 4, 5
• X-ray has limited sensitivity for carpal bone fractures (14-59%), particularly scaphoid, capitate, pisiform, trapezium, hamate, and triquetrum 5
• Unnecessary concurrent imaging of multiple regions (wrist, forearm, elbow) in pediatric patients shows limited benefit (1.7%) and increases radiation exposure 6
• Routine use of CT for metacarpal and digital fractures during acute injury is not indicated 1

Pediatric Considerations

• X-ray remains the gold standard for investigating forearm injuries in children despite emerging alternatives like ultrasound 7
• Targeted imaging based on physical examination findings is preferred over concurrent imaging of multiple regions (wrist, forearm, elbow) 6