Introduction
Recognising scaphoid fractures is particularly important given the unusual blood supply of the scaphoid bone. Around 80% of the blood supply is derived from the
Epidemiology
- Incidence: 20.00 cases per 100,000 person-years
- Peak incidence: 20-30 years
- Sex ratio: more common in males 7:1
<1 | 1-5 | 6+ | 16+ | 30+ | 40+ | 50+ | 60+ | 70+ | 80+ |
Aetiology
- Falling onto an outstretched hand (FOOSH)
- Contact sports: The peak incidence during the autumn is thought to correlate with the start of football and rugby activities at school.
Clinical features
- Pain along the radial aspect of the wrist, at the base of the thumb
- Loss of grip / pinch strength
Signs:
- 1. Point of maximal tenderness over the anatomical snuffbox
- This is a highly sensitive (around 90-95%), but poorly specific test (<40%) in isolation
- 2. Wrist joint effusion
- Hyperacute injuries (<4hrs old), and delayed presentations (>4days old) may not present with joint effusions.
- 3. Pain elicited by telescoping of the thumb (pain on longitudinal compression)
- 4. Tenderness of the scaphoid tubercle (on the volar aspect of the wrist)
- 5. Pain on ulnar deviation of the wrist
Clinical examination has a high diagnostic probability (sensitivity 100%; specificity 74%) when [1], [3], and [4] are positive on examination.
Investigations
- Plain film radiographs should be requested of the wrist in the anterior-posterior view, and lateral view
- 'Scaphoid views': posterioranterior (PA), lateral, oblique (with wrist pronated at 45º) and Ziter view (PA view with the wrist in ulnar deviation and beam angulated at 20º)
- The sensitivity in the first week of injury is only 80%
- A CT scan is superior to plain film radiographs, and may be requested in the context of ongoing clinical suspicion, planning operative management, or to determine the extent of fracture union during follow-up.
- MRI is considered the definite investigation to confirm or exclude a diagnosis
- NICE guidance from 2016 suggested the MRI should be considered the first-line imaging following clinical examination. However, this is still not common practice in the UK
- however, MRI is much more commonly used second-line when radiographs are inconclusive
Management
- immobilisation with a Futuro splint or standard below-elbow backslab
- referral to orthopaedics
- clinical review with further imaging should be arranged for7-10 days later when initial radiographs are inconclusive
Orthopaedic management
- dependent on the patient and type of fracture
- undisplaced fractures of the scaphoid waist
- cast for 6-8 weeks
- union is achieved in > 95%
- certain groups e.g. professional sports people may benefit from early surgical intervention
- displaced scaphoid waist fractures
- requires surgical fixation
- proximal scaphoid pole fractures
- require surgical fixation
Complications
- non-union → pain and early osteoarthritis
- avascular necrosis