Anatomical Snuffbox

Definition

Also known as foveola radialis . It is a skin depression.
Previously, it was used to put “tobacco powder” on it to snuff

Note

inhale it

it, so it has been named.

Location

Dorsum of hand, lateral aspect, distal of the styloid process of the radius, at the level of carpal bones “scaphoid & trapezium level“.

Shape

The anatomical snuffbox is triangular shaped.

Boundaries

Medially: Extensor pollicis longus (EPL) tendon
Laterally: Abductor pollicis longus (APL) & extensor pollicis brevis (EPB) tendons

The proximal border: Styloid process of the radius.
The distal border: Union of the two borders(medial & lateral) of the triangle

Note

Snuffbox shape

The floor: Scaphoid & trapezium
The roof: Skin, fascia (superficial & deep)

Note: The anatomical snuffbox is more noticeable if the thumb is extended & abducted .

Lateral view, Right hand

The Contents

1. Radial artery (branch of Brachial artery).

2. Cephalic vein (complement of Dorsal venous network of hand).

3. Superficial branch (branch of Radial nerve ).

4. Tendons of extensor carpi radialis longus & brevis muscles.

Note\ Easy way to memorize the contents of
The anatomical snuffbox .

CARTs

1. C ephalic vein
2. A rtery (radial)
3. R adial nerve (Superficial branch)
4. T endons of ECRL & ECRB

Lateral view, Right hand

Clinical importanc

1. It is one of the most important spots for palpation of Radial artery pulse in the Upper limb.

2. It uses to test the acting of some muscles:

If the Extensor pollicis brevis & Extensor pollicis longus are acting normally, EPB’s tendon can be felt on the lateral side of the anatomical snuffbox & EPL’s tendon can be felt on the medial side of it, when the thumb is extended against resistance at the metacarpophalangeal joint.

Scaphoid fracture

The scaphoid is the most carpal bone more likely to fracture.

Possible causes of Scaphoid fracture

1. Falling on extended hand.
2. Injuries during doing some sports.
3. Car accidents

extended hand

The symptoms

1. Pain and tenderness at the anatomical snuffbox which increases during hand dorsiflexion & abduction.
2. Swelling.

The diagnosis

1. Somatically, the specialist will look for any swelling & bruising on the lateral side of the hand.

2. Scrutiny, the patient will be examined through X-rays, Magnetic resonance imaging (MRI) scan & Computerized tomography (CT) scan.

Note/ The fracture may take 10-14 days to be noticed at X-rays because the blood supply to the proximal end of the bone will be decreased and that leads to bone attrition.

The treatment

1. The treatment will take about 3 months by splint or cast if the bone is non-displaced.
2. The treatment may need surgery if the fracture is acute.

Lateral view, Right hand

References

Moore - Clinically Oriented Anatomy (7th Edition) 686,751,686(B6.4)

SNELL'S CLINICAL ANATOMY BY REGIONS (10th Edition) 237-238-239,294-295,281-282,462,464.

Scaphoid Fracture of the Wrist- OrthoInfo- https://orthoinfo.aaos.org/en/diseases--conditions/scaphoid-fracture-of-the-wrist/

Scaphoid Fracture- Cleveland Clinic- https://my.clevelandclinic.org/health/diseases/22240-scaphoid-fracture

https://youtu.be/0CjQ5snNvos

Pinterest- https://pin.it/6ceRjIH
Grant Atlas Of Anatomy (13th Edition) 593(D6.89)
Netter- Atlas Of Human Anatomy (6th Edition) 454