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.
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