The Carpal Tunnel and Anatomical Snuffbox Flashcards
What forms the borders of the carpal tunnel?
The carpal arch
The flexor retinaculum
What is the carpal tunnel?
A narrow passageway found on the anterior portion of the wrist
Where does the carpal arch insert?
The scaphoid and trapezium tubercles to the hook of hamate and pisiform
What is in the carpal tunnel?
Tendon of flexor pollicis longus
4 tendons of flexor digitorum profundus
4 tendons of flexor digitorum superficialis
Median nerve
What does the recurrent branch of the median nerve supply?
Thenar muscle group
What does the palmar digital branch of the median nerve supply?
Sensory innervation of palmar skin and dorsal nail beds of lateral three and a half fingers
Motor innervation of the lateral two lumbricals
What is carpal tunnel syndrome caused by?
Compression of the median nerve due to thickened ligaments and endon sheaths
Symptoms of carpal tunnel syndrome?
Numbness, tingling and pain in distribution of median nerve. Pain can radiate to forearm. Often worse in the morning.
What can carpal tunnel syndrome cause?
Weakness and atrophy if thenar muscles
What tests can be done for CTS?
Tap nerve in carpal tunnel to elicit pain in median nerve distribution (Tinel’s sign)
Flex wrist for 60 secs to elicit pain and numbness
How can CTS be treated?
Splint to dorsiflex the wrist overnight
Injection of corticosteroids
Surgical decompression
What is the anatomical snuffbox?
Triangular depression on the lateral aspect of the dorsum of the hand at the level of the carpal bones
Borders of the anatomical snuffbox?
Medial - tendon of extensor pollicis longus
Lateral - tendon of abductor pollicis longus and extensor pollicis brevis
Proximal - styloid process of radius
Floor - scaphoid and trapezium
Roof - skin
Contents of the anatomical snuffbox?
Radial artery
Superficial branch of the radial nerve
Cephalic vein
What does the superficial branch of the radial nerve innervate?
Skin of lateral three and a half digits on dorsum of hand and associated palmar area
