Anatomic snuffbox

Anatomic Snuffbox (also known as the radial fossa) is a triangular depression on the lateral aspect of the dorsum of the hand, at the level of the carpal bones, specifically between the styloid process of the radius and the scaphoid and trapezium bones. It becomes more prominent when the thumb is extended.

Anatomy

The anatomic snuffbox is bordered by three tendons: the abductor pollicis longus and extensor pollicis brevis tendons on the lateral side, and the extensor pollicis longus tendon on the medial side. The floor of the snuffbox is formed by the scaphoid and trapezium bones as well as the base of the first metacarpal bone. The radial artery passes through the snuffbox, making it a palpable pulse point. Additionally, the superficial branch of the radial nerve provides sensory innervation to the area.

Clinical Significance

The anatomic snuffbox is clinically significant for several reasons. It is a landmark for the palpation of the radial artery, which may be necessary for assessing the circulatory status of the hand or for radial artery cannulation. Pain or tenderness in the snuffbox can be indicative of a scaphoid fracture, a common injury from a fall on an outstretched hand. Due to the scaphoid's poor blood supply, fractures in this area can lead to avascular necrosis, making prompt diagnosis and treatment crucial.

Diagnostic Tests

Physical examination and imaging tests such as X-rays, MRI, and CT scans can be used to diagnose injuries or conditions associated with the anatomic snuffbox. The sensitivity of physical examination can be enhanced by specific maneuvers, such as the scaphoid shift test, to detect instability or injury.

Treatment

Treatment for conditions affecting the anatomic snuffbox, such as scaphoid fractures, varies depending on the severity of the injury. Options may include immobilization with a cast or splint, or surgical intervention in the case of non-union or displacement of the fracture. Rehabilitation exercises may also be recommended to restore strength and flexibility after immobilization.

See Also

• Carpal bones
• Radius (bone)
• Hand anatomy
• Radial artery

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