Question

Which part of scaphoid fracture is most susceptible to avascular necrosis?

• A. Distal 1/3rd
• B. Middle 1/3rd
• C. Proximal 1/3rd
• D. Scaphoid Tubercle

Answer 1

The Correct Option is C

The scaphoid bone is an important bone in the wrist that aids in various wrist movements. Understanding its blood supply is crucial in physiology and clinical practice. The question addresses which part of the scaphoid is most susceptible to avascular necrosis, which is a condition where bone tissue dies due to a lack of blood supply.

The scaphoid receives its blood supply primarily from the radial artery. However, the blood flow to the scaphoid is in a retrograde fashion, meaning it flows from the distal to the proximal segments of the bone.

In the event of a scaphoid fracture, especially if the fracture involves the proximal segment, the blood supply can be interrupted. The blood flow being retrograde means that the proximal portion of the scaphoid is the last to receive blood from the vascular supply. Therefore, any fracture or injury primarily affecting or isolating this part can significantly hinder its blood supply.

Given this anatomical and physiological explanation, the Proximal 1/3rd of the scaphoid bone is the region most susceptible to avascular necrosis. The interruption of blood supply predominantly affects the proximal segment because it relies almost entirely on the blood flow's distal-to-proximal direction, showcasing its vulnerability in the event of fractures.

Section of Scaphoid	Susceptibility to Avascular Necrosis
Distal 1/3rd	Low
Middle 1/3rd	Moderate
Proximal 1/3rd	High
Scaphoid Tubercle	Low