Anatomical snuff box

Question 1

Borders of the anatomical snuff box

Answer 1

As the snuffbox is triangularly shaped, it has three borders, a floor, and a roof:

• Ulnar (medial) border: Tendon of the extensor pollicis longus.
• Radial (lateral) border: Tendons of the abductor pollicis longus and extensor pollicis brevis.
• Proximal border: Styloid process of the radius.
• Floor: Carpal bones; scaphoid and trapezium.
• Roof: Skin

Question 2

Contents

Answer 2

The main contents

1) the radial artery,
2) a branch of the radial nerve, and
3) the cephalic vein

Question 3

Clinical relevance

Answer 3

In the anatomical snuffbox, the scaphoid and the radius articulate to form part of the wrist joint. In the event of a blow to the wrist (e.g falling on a outstretched hand), the scaphoid takes most of the force. If localised pain is reported in the anatomical snuffbox, a fracture of the scaphoid is the most likely cause.

The scaphoid has a unique blood supply, which runs distal to proximal. A fracture of the scaphoid can disrupt the blood supply to the proximal portion – this is an emergency. Failure to revascularise the scaphoid can lead to avascular necrosis, and future arthritis for the patient