Scaphoid Fracture
The scaphoid bridges the proximal and distal carpal rows and plays a major role in carpal stability.
Approximately 80% of its blood supply enters dorsally and travels in a predominantly retrograde direction toward the proximal pole.
This explains why proximal pole fractures have:
- Slower union
- Greater nonunion risk
- Greater osteonecrosis risk
Most fractures occur through the waist.
Classification by location
- Distal tubercle
- Distal pole
- Waist
- Proximal pole
Approximately 65% to 80% occur through the waist.
Herbert and Fisher classification
Type A: Stable acute fracture
A1
Tubercle fracture.
A2
Incomplete waist fracture.
Type B: Unstable acute fracture
B1
Distal oblique fracture.
B2
Complete waist fracture.
B3
Proximal pole fracture.
B4
Transscaphoid perilunate fracture dislocation.
B5
Comminuted fracture.
Type C
Delayed union with widening or cystic change.
Type D
Established nonunion.
D1
Fibrous union.
D2
Pseudoarthrosis or mobile nonunion.
Russe classification
Based on fracture orientation.
Horizontal oblique
More compressive and generally stable.
Transverse
Intermediate.
Vertical oblique
Shear dominant and mechanically unstable, with greater nonunion risk.
SNAC wrist
Untreated scaphoid nonunion can progress to scaphoid nonunion advanced collapse.
Degenerative progression broadly begins at the radial styloid and distal scaphoid, progresses across the radioscaphoid articulation, and involves midcarpal joints while the radiolunate articulation is relatively preserved until late disease.
