Scaphoid fracture

Scaphoid fractures (i.e. fractures through the scaphoid bone) are common, in some instances can be difficult to diagnose, and can result in significant functional impairment.

Scaphoid fractures account for 70-80% of all carpal bone fractures 1. Although they occur essentially at any age, adolescents and young adults are most commonly affected 1. Older patients falling in a similar manner are more likely to sustain a distal radial fracture (usually a Colles fracture).

Classically there can be pain in anatomical snuffbox which is thought to have a sensitivity of ~90% and a specificity ~40% 4.

The usual mechanism is falling on an outstretched hand with resultant hyper-extension of the wrist or purely compressive force 7. Occasionally stress fractures are also encountered although these are less common, and only usually seen in athletes (e.g. shot-putters or gymnasts) 8.

Fractures can occur essentially anywhere along the scaphoid, but distribution is not even 9:

  • waist of scaphoid: 70-80%
  • proximal pole: 20%
  • distal pole (or so-called scaphoid tubercle): 10%
Classification

See: Mayo classification of scaphoid fractures.

Plain radiograph

Plain radiographs of the wrist, including dedicated scaphoid views are the initial imaging modality of choice. It should however be noted that initial radiograph can miss from 5-20% of fractures in the acute setting 1.

Features include:

  • visualisation of the fracture +/- displacement
  • soft tissue swelling and lateral displacement of the adjacent fat pads
    • scaphoid fat pad sign: obliteration or lateral displacement of a straight/convex lucent line on the lateral aspect of the scaphoid 11
  • associated scapholunate ligament disruption (Terry Thomas sign) which can be accentuated with a clenched fist view

If AVN develops the first sign will be slight sclerosis. This can be on account of the rest of the wrist undergoing demineralisation due to immobilisation, whereas the proximal portion being bereft of blood supply retains its calcium. With time the proximal part undergoes osteonecrosis, becomes increasingly sclerotic and can 'implode' and fragment with secondary osteoarthritic changes 9.

Report checklist

In addition to stating that a fracture is present, a number of features should be sought and commented upon:

  • fracture
    • location (distal pole, waist, proximal pole)
    • involvement of articular surfaces
    • displacement
    • humpback deformity due to angulation between proximal and distal parts
  • alignment
  • associated fractures (e.g. Colles fracture or other carpal bone fractures)
  • evidence of avascular necrosis if the fracture is subacute

Importantly if no fracture is seen it is essential to recommend repeat x-rays (including dedicated scaphoid views) in 7-10 days 1. If these repeat films are negative also, then MRI (or bone scan if MRI is unavailable) should be recommended if clinical suspicion persists 1.

CT

CT may be used for diagnosis when plain films are normal because it is readily available and quick 12. Reported sensitivities, specificities and negative predictive values for CT have been reported CT to be 89-90%, 85-100% and 97-98% respectively. CT may be insensitive to trabecular injury 5. CT is useful for staging scaphoid fractures if surgery is considered and when fractures of the carpus are extensive or complex. CT also is useful in assessing bone union 8.

MRI

MRI is the most sensitive modality for trabecular fractures, and this can detect completely undisplaced fractures , especially in the first 24 hours following injury9, 13. It is also useful in assessing for avascular necrosis.

Nuclear medicine

Although bone scans are more sensitive than plain film, they are usually reserved for patients with ongoing pain despite normal serial plain films 8, 13. Bone scans will be most sensitive 3-4 days following the injury. An occult fracture will appear as a region of increased uptake, whereas avascular necrosis will demonstrate a photopaenic region at the lower pole of the scaphoid.

Management options can broadly be divided into:

  • immobilisation with cast application
  • internal fixation for displaced fragments, usually with a headless self-compressing screw 10
  • non-union can be managed with internal fixation and bone grafting 10

Non-union occurs in 5-10% of cases 14. Factors affecting prognosis:

  • location 9
    • distal pole: excellent likelihood of union (~100%)
    • waist: ~10-20% chance of non-union
    • proximal pole: ~30-40% chance of non-union
  • vertically oriented fracture line
  • fragment displacement of >1mm
  • ligamentous instability: increased scapholunate angle (i.e. >60º or radiolunate or capitolunate angle >15º

The major complication of scaphoid fractures is non-union or malunion leading to instability and secondary osteoarthritic change. Hence surgical treatment for displaced fractures or angulation.

A number of other specific complications are encountered from time to time:

The term scaphoid derives from the Greek word for boat. The bone profile is thought to look like a boat or skiff.


Share article

Article Information

rID: 2021
Synonyms or Alternate Spellings:
  • Carpal navicular fracture
  • Scaphoid fractures
  • Carpal navicular fractures
  • Scaphoid bone fractures
  • Scaphoid bone fracture
  • Fracture of scaphoid bone
  • Scaphoid fx

Support Radiopaedia and see fewer ads

Cases and Figures

  • Drag
    Case 1: initial radiograph
    Drag here to reorder.
  • Drag
    Case 2
    Drag here to reorder.
  • Drag
    Case 3
    Drag here to reorder.
  • Drag
    Scaphoid fracture...
    Case 4: with early avascular necrosis
    Drag here to reorder.
  • Drag
    Case 5: trans-scaphoid perilunate dislocation
    Drag here to reorder.
  • Drag
    Case 6
    Drag here to reorder.
  • Drag
    Case 7
    Drag here to reorder.
  • Drag
    Case 8
    Drag here to reorder.
  • Drag
    Scaphoid fracture
    Case 9
    Drag here to reorder.
  • Drag
    Case 10
    Drag here to reorder.
  • Drag
    Case 11: distal
    Drag here to reorder.
  • Drag
    Case 12
    Drag here to reorder.
  • Drag
    Case 13: distal pole
    Drag here to reorder.
  • Drag
    Case 14
    Drag here to reorder.
  • Drag
    Case 15: with concurrent capitate fracture
    Drag here to reorder.
  • Drag
    Case 16: with distal radial fracture
    Drag here to reorder.
  • Drag
    Case 17
    Drag here to reorder.
  • Drag
    Case 18: with delayed healing in scaphoid fracture
    Drag here to reorder.
  • Drag
    Case 19: with AVN
    Drag here to reorder.
  • Drag
    Case 20: on ultrasound
    Drag here to reorder.
  • Drag
     Case 21
    Drag here to reorder.
  • Drag
    Case 22: treated with Herbert scew
    Drag here to reorder.
  • Drag
    Case 23: with AVN
    Drag here to reorder.
  • Drag
    Case 24: with DISI
    Drag here to reorder.
  • Drag
    Case 25: with non-union
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.