Scaphoid fracture

Background

• Most commonly fractured carpal bone
• Occurs via FOOSH or axial load directed along thumb's metacarpal
• Most common fracture at the waist of the scaphoid
• Avascular necrosis
  • Most commonly associated with proximal fractures (blood supply enters the distal part of the bone)

Clinical Features

Anatomical snuff box

• Pain along radial aspect of wrist
• Localized tenderness in anatomic snuffbox
• Pain elicited by axial pressure directed along thumb's metacarpal

Differential Diagnosis

Carpal fractures

AP view

• Scaphoid fracture
• Lunate fracture
• Triquetrum fracture
• Pisiform fracture
• Trapezium fracture
• Trapezoid fracture
• Capitate fracture
• Hamate fracture

Evaluation

Scaphoid waist fracture

Scaphoid pseudarthrosis, before and after treatment with Herbert screw.

Workup

• X-ray
  • Obtain both standard and scaphoid views
  • Up to 10% of initial radiographs fail to detect a fracture
• MRI
  • Gold-standard in cases in which high index of suspicion remains despite negative x-ray

Diagnosis

Scaphoid fractures occur in three locations: (A) Distal tubercle, (B) waist, and (C) proximal pole.

• Assess for instability:
  • Oblique fracture
  • >1mm of displacement
  • Rotation
  • Comminution
  • Carpal instability pattern is present

Management

All patients with clinical suspicion should be treated regardless of x-ray findings

General Fracture Management

• Acute pain management
• Open fractures require immediate IV antibiotics and urgent surgical washout
• Neurovascular compromise from fracture requires emergent reduction and/or orthopedic intervention
• Consider risk for compartment syndrome

Immobilization

• Stable fracture: short-arm thumb spica splint in dorsiflexion and radial deviation
• Unstable fracture: long-arm thumb spica splint

Disposition

• Refer to a hand surgeon because may lead to osteonecrosis if not properly recognized/treated
• 25% of those with initially neg xray will actually have a fracture (typically found on delay xray or other modality)
• Repeat Wrist and scaphoid X-rays should be obtained 2-3 weeks after initial injury to assess for fracture if suspicion is high.
• Immobilization may be required for at least 6-12 wks

See Also

• Carpal fractures