Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA
The anatomical snuffbox is a small triangular depression located on the dorsoradial aspect of the wrist.People used this space to place and sniff the powdered tobacco or “snuff”, hence the name.The base of this triangular space is proximal with the apex pointing towards the thumb.The anatomical snuffbox is seen better when the thumb is extended. It can also be seen well when the palm is placed flat on the table and the thumb is lifted off of the table.
Speaking about its boundaries, laterally ,there are the tendons of the Abductor pollicis longus and the Extensor pollicis brevis and forming the ulnar border is the Extensor pollicis longus tendon.The Abductor pollicis longus originates from the radius and ulna.The 2nd tendon of Extensor pollicis brevis is inserted into the base of the proximal phalanx.The Extensor pollicis brevis originates from the radius.The Abductor pollicis longus and the Extensor pollicis brevis tendons belong to the 1st dorsal compartment while the Extensor pollicis longus tendon is present in the 3rd dorsal extensor compartment.All three muscles are supplied by the posterior interosseous nerve ,branch of the radial nerve.The contents of the anatomical snuffbox are the radial artery which forms the deep palmar arch,superficial radial nerve and the cephalic vein.The floor is formed by scaphoid and trapezium carpal bones.
Talking about the clinical conditions pertaining to the anatomical snuffbox, the fracture of the scaphoid bone is a common carpal bone injury,the diagnosis of which is confirmed by tenderness in the anatomical snuffbox.One is supposed to always consider a scaphoid fracture and treat the same even if a fracture is not visible on the X-ray.Immobilize the wrist in a thumb spica and see the patient in 10 days to 2 weeks for reevaluation and X-rays.It is of paramount importance to immobilize the wrist early as the rate of non-union increases if there is a delay in diagnosis by 4 weeks or more.
Another related condition is the attrition rupture of the EPL tendon.The EPL tendon is most commonly affected in fractures of the distal radius.Rupture is more common in undisplaced fractures as compared to displaced fractures.The patient will be unable to lift the thumb up,especially when the palm is placed down on a flat surface.The best option for this condition is a tendon transfer procedure where the tendon of Extensor Indicis Proprius is transferred to the EPL tendon.Another clinical significance of the anatomical snuffbox is to locate it before giving steroid injections in case of De Quervain syndrome.The tendons of the radial boundary of the snuffbox are the ones involved in De-Quervain syndrome.
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