Describe the anatomical snuffbox with its boundaries and contents. Add a note on scaphoid fracture.

Definition

• So named because ground tobacco was placed there for sniffing

Boundaries

• Extensor pollicis longus hooks around the dorsal (Lister) tubercle of the radius, which acts as a pulley — and where the tendon may rupture after a Colles fracture

Contents and Relations

• Radial artery — crosses the floor obliquely, on its way to the first dorsal interosseous space; its pulse can be felt here
• Superficial branch of the radial nerve — in the roof, crossing the tendons
• Cephalic vein — begins in the roof from the dorsal venous network
• Termination of the dorsal digital branches

Clinical Importance — Scaphoid Fracture

• Tenderness in the anatomical snuffbox after a fall on the outstretched hand means a scaphoid fracture until proved otherwise
• The scaphoid is the most commonly fractured carpal bone
• Usually at the waist of the bone
• The initial radiograph is often normal — the fracture line may not appear for 10–14 days
• Therefore treat on clinical suspicion: immobilise in a scaphoid cast and repeat the radiograph, or obtain MRI
• A missed scaphoid fracture is one of the commonest sources of medicolegal difficulty in orthopaedics

Other Applied Points

• The radial pulse can be felt in the snuffbox against the scaphoid, an alternative to the usual site at the wrist

Summary Table