When is an X-ray (X-ray) recommended for ambulatory patients with extremity injuries?

X-ray Recommendations for Ambulatory Extremity Injuries

X-ray is recommended as first-line imaging for ambulatory patients with extremity injuries when clinical decision rules are positive, specifically the Ottawa Ankle Rules for lower extremity injuries or when there is clinical suspicion of fracture based on mechanism of injury, point tenderness over bony structures, or inability to bear weight. 1, 2

Initial Imaging Approach by Anatomic Region

Ankle Injuries (Adults and Children ≥5 Years)

Apply the Ottawa Ankle Rules to determine X-ray necessity: 1

• Order X-ray if ANY of the following are present:

  • Inability to bear weight immediately after injury 1
  • Inability to ambulate for 4 steps in the emergency department 1
  • Point tenderness over the medial malleolus, posterior edge or inferior tip of the lateral malleolus, talus, or calcaneus 1

• Standard ankle radiographic protocol includes three views: anteroposterior, lateral, and mortise views (must include base of fifth metatarsal) 1, 2

• Weight-bearing radiographs are preferred when possible, particularly for assessing fracture stability (medial clear space <4 mm confirms stability) 1, 2

The Ottawa Ankle Rules demonstrate 92-100% sensitivity and 16-51% specificity for detecting fractures, with implementation reducing emergency department stay by up to 20 minutes 1

Hand and Wrist Injuries

X-ray is always indicated as initial imaging for suspected acute hand and wrist trauma: 1

• Wrist injuries require 3-view examination: posteroanterior, lateral, and 45-degree semipronated oblique 1
• Hand injuries require 3-view examination: posteroanterior (entire hand or injured finger), lateral, and externally rotated oblique 1
• Thumb injuries require minimum 2-view examination, though oblique projection increases diagnostic yield 1

Upper Extremity Injuries

X-ray is first-line imaging for suspected fractures in ambulatory patients with upper extremity trauma, particularly in throwing athletes, weightlifters, or those involved in upper extremity weight-bearing sports presenting with chronic pain 3

Critical Exclusionary Criteria (Do NOT Apply Ottawa Rules)

Order X-ray regardless of clinical decision rules if ANY of the following are present: 1, 2

• Penetrating trauma 2
• Pregnancy 2
• Skin wounds requiring assessment 2
• Altered sensorium 2
• Neurologic abnormalities or peripheral neuropathy (including diabetic neuropathy) 1, 2
• Underlying bone disease 2
• Age <5 years 1

For diabetic patients with suspected Charcot neuro-osteoarthropathy, bilateral plain X-rays are recommended as initial imaging 2

When Initial X-rays Are Negative but Clinical Suspicion Persists

For Hand/Wrist Injuries:

• Option 1: Place in short arm cast and repeat X-rays at 10-14 days (delays diagnosis and may impair function) 1
• Option 2: CT without IV contrast to exclude or confirm suspected fractures, particularly useful for intra-articular distal radius fractures 1
• Option 3: MRI without IV contrast detects occult fractures and concomitant ligament injuries, though one study showed no difference in outcomes compared to radiography alone 1

For Ankle Injuries with Persistent Pain (1-3 Weeks):

MRI without IV contrast or CT without IV contrast are equivalent alternatives for detecting occult fractures when initial radiographs are negative 1

Severe Limb Trauma with Vascular Concerns

CT angiography is recommended when ANY of the following are present: 1

• Externalized bleeding of arterial origin 1
• Injury site near main vascular axis 1
• Non-expanding hematoma 1
• Isolated neurological deficit 1
• Ankle-brachial index (ABI) <0.9 1

CT angiography demonstrates 96.2% sensitivity and 99.2% specificity for detecting vascular injuries in limb trauma 1

Common Pitfalls to Avoid

• Do not apply Ottawa Ankle Rules in patients with neuropathy (including diabetics), as sensitivity is significantly reduced 2, 4
• Avoid ankle manipulation prior to radiographs unless neurovascular deficit or critical skin injury is present, to prevent complications 1
• Do not perform foot radiographs routinely with ankle radiographs unless specific foot injury suspected, as yield is low except for fifth metatarsal base 1
• In elderly patients (≥65 years) or those with upper extremity injuries, radiography has reduced sensitivity for unstable fractures; consider lower threshold for advanced imaging 5
• For patients on long-term bisphosphonates (3-5 years) with thigh/groin pain, obtain X-ray initially, but if negative with persistent symptoms, proceed directly to MRI 2