## Scaphoid Fracture: Anatomical Distribution **Key Point:** The waist (middle third) of the scaphoid is the most common fracture site, accounting for approximately 60–70% of all scaphoid fractures. ### Frequency by Location | Location | Frequency | Clinical Significance | |----------|-----------|----------------------| | **Waist** | 60–70% | Most common; moderate blood supply; healing time 8–12 weeks | | Distal pole | 20–30% | Better blood supply; faster healing (6–8 weeks) | | Proximal pole | 5–10% | Poorest blood supply; highest nonunion risk (10–15%); longest healing (12–16 weeks) | | Tubercle | Rare | Avulsion injury; usually stable | ### Blood Supply Correlation **High-Yield:** The retrograde blood supply enters at the waist and distal pole. The proximal pole is supplied only by small branches, making it vulnerable to avascular necrosis (AVN) if displaced or untreated. **Clinical Pearl:** Proximal pole fractures have the worst prognosis due to tenuous blood supply and are prone to nonunion and AVN, even with appropriate treatment. ### Mechanism Waist fractures typically result from a fall on an outstretched hand (FOOSH) with the wrist in dorsiflexion and radial deviation—the most common mechanism of scaphoid injury. 
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