## Scaphoid Blood Supply **Key Point:** The scaphoid has a retrograde blood supply pattern — the distal pole receives blood first, and the proximal pole is supplied last, making it most vulnerable to avascular necrosis. ### Arterial Supply Pattern The scaphoid receives its blood supply primarily from branches of the radial artery: 1. **Dorsal carpal branch of radial artery** — enters via dorsal ridge, supplies 70–80% of the bone 2. **Palmar carpal branch** — enters via palmar tubercle, supplies distal pole 3. **Retrograde flow** — blood enters distally and flows proximally ### Clinical Significance **High-Yield:** The proximal pole has **tenuous blood supply** and is the last area to be perfused. Fractures through the proximal third or waist can disrupt the main arterial pedicle, leading to: - Delayed union - Non-union - Avascular necrosis (AVN) **Clinical Pearl:** Proximal pole fractures have a 10–12% risk of AVN, while distal pole fractures have <5% risk — a direct consequence of the retrograde vascular pattern. ### Mnemonic **RDP** — **R**adial **D**orsal **P**ole (primary supply to proximal pole via dorsal carpal branch of radial artery). 
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