Table Of Contents
Scaphoid Fracture
The scaphoid lies obliquely across the two rows of carpal bones and is in line with the thumb and forearm. Fracture is commonly caused by forced carpal movement and compression (fall on dorsiflexed hand). The fracture can occur in 3 locations: distal tubercle, waist and proximal pole. Diagnosis can be made using a radiograph, but CT or MRI may be obtained for confirmation. Treatment includes prolonged cast immobilization, percutaneous surgical fixation or open reduction and internal fixation.
Scaphoid fractures account for 75% of all carpal fractures and 15% of acute wrist injuries. It is more common in the third decade of life. They are rare in the elderly and in children.
Anatomical location of scaphoid fractures
| Location | Description |
|---|---|
| Distal tubercle (10%) | Distal oblique fractures are unstable and may predispose to non-union or malunion. May occur in children |
| Waist (65%) | Waist fractures are unstable and may predispose to non-union or malnunion |
| Proximal pole (25%) | Fractures of the proximal pole are less likely to heal since blood supply of the scaphoid arises from the distal pole |
- Mechanism of injury
- High-energy or low-energy fall on dorsiflexed hand
- Signs and symptoms
- Pain and tenderness over the tubercle (volar) and anatomical snuffbox (dorsal)
- Fullness in the anatomical snuffbox
- Wrist pain worse with circumduction
- Pain with resisted pronation
- Deformity may be absent
- Physical examination
- Scaphoid compression test: pain is reproduced with axial load applied through the thumb metacarpal.
- Tenderness in the anatomical snuffbox (dorsal)
- Tenderness over the tubercle (volar)
- Investigations
- X-ray (PA with wrist in ulnar deviation, lateral, semi-pronated oblique view, semi-supinated olique): recent fracture may show only in the oblique view. Waist fracture is best seen on scaphoid view (wrist in 20 degrees of ulnar deviation). If radiographs are negative it may be repeated in 14 – 21 days.
- MRI: for diagnosing occult fractures < 23 hours, ligamentous injuries and vascularity of the proximal pole
- CT scan: evaluate fracture location, angulation, displacement, fragment size, extent of collapse, and progression of non-union or union after surgery
- Signs of displacement or instability on plain radiograph
- Oblique or vertical fracture line
- Angulation of the distal fragment
- Foreshortening of the scaphoid image
- Signs of delayed union or non-union on plain radiograph
- Ring sign: round scaphoid tubercle on PA view
- DISI: dorsally tilted proximal pole and lunate on the lateral view
- Avascular necrosis: Sclerosis of the proximal pole
- Conservative treatment
- Long arm thumb spica or short arm thumb spica immobilization for 6 – 8 weeks: for non-displaced wait or tubercle fracture
- Indications for operative treatment
- Significant displacement
- Fracture associated with perilunate dislocation
- Comminuted fracture
- Unstable fracture e.g. proximal pole fracture
- Unstable vertical or oblique fracture
- Non-union
- Operative treatment
- Percutaneous screw fixation
- Dorsal approach: proximal pole fracture
- Volar approach: waist and distal pole fracture
- Open reduction internal fixation: dorsal or volar approach as percutaneous screw fixation.
- Percutaneous screw fixation
- Complications of scaphoid fracture
- Avascular necrosis of the proximal fragment: associated with small proximal pole fractures
- Non-union
- Osteoarthritis: as a result of non-union or avascular necrosis
