Carpal tunnel Flashcards
Borders of the carpal tunnel?
Formed by two layers: a deep carpal arch and a superficial flexor retinaculum.
Carpal Arch
- Concave on the palmar side
- Formed laterally by the scaphoid and trapezium tubercles
- Formed medially by the hook of the hamate and the pisiform
Flexor Retinaculum
- Thick connective tissue
- Turns the carpal arch into the carpal tunnel by bridging the space between the medial and lateral parts of the arch.
- Originates on the lateral side and inserts on the medial side of the carpal arch.
Contents of carpal tunnel?
The carpal tunnel contains a total of 9 tendons, surrounded by synovial sheaths, and the median nerve.
Tendons within the carpal tunnel?
The tendon of flexor pollicis longus
4 tendons of flexor digitorum profundus
4 tendons of flexor digitorum superficialis
What are the tendons within the carpal tunnel surrounded by and what does this allow for?
The 8 tendons of the flexor digitorum profundus and flexor digitorum superficialis are surrounded by a single synovial sheath.
The tendon of flexor pollicis longus is surrounded by its own synovial sheath.
These sheaths allow free movement of the tendons.
Once it passes through the carpal tunnel, the median nerve divides into 2 branches - what are they?
The recurrent branch
and
palmar digital nerves
List some causes of carpal tunnel syndrome
(TRAMP)
Trauma
Rheumatoid arthritis
Acromegaly
Myxodema
Pregnancy
How can you test for carpal tunnel syndrome?
Tinel’s Sign - Tapping the nerve in the carpal tunnel to elicit pain in median nerve distribution
Phalen’s manoeuvre - Holding the wrist in flexion for 60 seconds to elicit numbness/pain in median nerve distribution
Treatment of carpal tunnel syndrome?
Splint - holding the wrist in dorsiflexion overnight to relieve symptoms.
Corticosterioid injections into the carpal tunnel
Surgical decompression of the carpal tunnel may be required.
