Week 6 - The Carpal Tunnel Flashcards
What two structures make up the carpal tunnel?
Body of the arch = carpal arch
Roof of the arch = flexor retinaculum
What makes up the lateral border of the palmar arch?
Scaphoid and trapezium
What makes up the medial border of the palmar arch
The hook of hamate and the pisiform
What is the flexor retinaculum?
A layer of thick connective tissue
Give the origins and insertions of the flexor retinaculum.
Origin = scaphoid and trapezium (i.e. the lateral border of the carpal arch) Insertion = hook of hamate and pisiform (i.e. medial border of the carpal arch)
How many things pass through the carpal tunnel?
10
9 tendons and a nerve
Give the contents of the carpal tunnel
9 tendons -
4 x flexor digitorum superficialis
4 x flexor digitorum profundus
1 x flexor pollicis longus
1 nerve - median
How many nerve sheaths bind the tendons which pass through the carpal tunnel?
2
1 binds the 8 flexor digitorum tendons
1 binds FPL tendon
What is carpal tunnel syndrome?
Compression of the median nerve within the carpal tunnel
What is the cause of carpal tunnel syndrome?
May be caused by thickened tendon sheaths or ligaments, but most often idiopathic
If carpal tunnel syndrome is left untreated, what is the main risk?
Atrophy and weakness of the thenar muscles
What are the symptoms of carpal tunnel syndrome?
Numbness, tingling and pain in the distribution of the median nerve
What is Tinel’s sign?
Tinel’s sign is a test used to identify carpal tunnel syndrome
It is performed by tapping the nerve in the tunnel, which produces pain
What is Phalen’s manoevre?
It is a test used to diagnose carpal tunnel syndrome
It involves flexing the wrist for 1 minute, which produces pain
What two tests can be performed to diagnose carpal tunnel syndrome?
Tinel’s sign
Phalen’s manoevre
