How does displacement and proximal pole location influence scaphoid fracture management and AVN risk?

• A. Non-displaced diaphyseal fractures are often cast; displaced fractures or proximal pole fractures have higher AVN risk and may require surgical fixation.
• B. All scaphoid fractures require surgical fixation regardless of displacement or pole.
• C. Proximal pole fractures have lower AVN risk and always heal with casting.
• D. Distal pole fractures have the highest AVN risk.

Answer: (A)

Displacement and where the fracture sits along the scaphoid affect both blood supply and healing potential. The scaphoid’s blood mainly enters from the distal pole and travels proximally. If a fracture is non-displaced, especially in the diaphysis, the blood supply to both fragments is often preserved, so immobilization in a cast can allow healing with a relatively low risk of avascular necrosis. When a fracture is displaced or involves the proximal pole, the vessels to the proximal fragment are more likely disrupted, increasing the risk of avascular necrosis and nonunion. In these cases, surgical fixation is often pursued to stabilize the fracture and improve chances of revascularization. Proximal pole fractures carry the highest AVN risk because the critical blood supply has to traverse the fracture site to reach the proximal fragment. Distal pole fractures tend to heal well and have a lower AVN risk, so casting can be adequate if the fracture is not displaced.