Anatomy, Shoulder and Upper Limb: Hand Anatomical Snuff Box

The anatomical snuffbox is a surface anatomy feature described as a triangular depression on the dorsum of the hand at the base of the thumb (see . Hand Anatomical Snuffbox). This depression becomes prominently visible with ulnar deviation of the wrist and abduction and extension of the thumb. The term “snuffbox” originates from the historical use of this area as a site for inhaling powdered tobacco, or dry snuff. The anatomical snuffbox appeared in surgical anatomy texts prior to 1850. Further elaboration of the region was provided in 19th-century works by anatomists such as Germain Cloquet and Marie-François Bichat. Widespread inclusion of the anatomical snuffbox in formal anatomical textbooks followed in the early 20th century. The anatomical snuffbox is bordered medially by the tendon of the extensor pollicis longus (EPL) and laterally by the tendons of the extensor pollicis brevis (EPB) and abductor pollicis longus (APL). The floor of this region consists of the scaphoid and trapezium bones, as well as the tendons of the extensor carpi radialis longus and extensor carpi radialis brevis. Palpable landmarks within the snuffbox include the styloid process of the radius proximally and the base of the 1st metacarpal bone distally. Structures contained within this region include the radial artery, the superficial branches of the radial nerve, and the cephalic vein. The anatomical snuffbox holds clinical relevance because the scaphoid bone, located at the floor of the snuffbox, is readily accessible to palpation (see . Scaphoid Bone of the Wrist). Following trauma, tenderness in this location may indicate a scaphoid fracture. Missed or delayed diagnosis of such a fracture may result in chronic pain and long-term functional impairment.