Carpal Tunnel

Question 1

What is the carpal tunnel?

___ canal
passage from ___ to ____
located ___
covered by _____

Answer 1

Osteofibrous canal
Passageway from the wrist to the hand
Located in the anterior wrist
Covered by connective tissue

Question 2

What forms the posterior boundary of the carpal tunnel?

proximal row (4) & distal row (4)

Answer 2

Carpal bones

Proximal row: Pisiform (p), Triquetrum (t1), Lunate (l), Scaphoid (s)
Distal row: Hamate (h), Capitate (c), Trapezoid (t2), Trapezium (t3)

Question 3

What are the boundaries of the carpal tunnel?

base including medial and lateral

anterior wall

Answer 3

Base of carpal arch:
Medially: Pisiform and hook of hamate
Laterally: Tubercles of scaphoid and trapezium
Anterior wall: Flexor retinaculum (connective ligament bridging the base of the carpal arch)

Question 4

What structures pass through the carpal tunnel? (10)

Answer 4

9 tendons:
4 Flexor digitorum profundus
4 Flexor digitorum superficialis
1 Flexor pollicis longus
1 nerve: Median nerve

Question 5

What are the anatomic relations between elements of the carpal tunnel?
Flexor digitorium superficialis and profundity relationship
Flexor pollicis tendon and flexor digitorium tendon relationship
Median nerve location with respect to all other tendons

Answer 5

Flexor digitorium superficialis is anterior to profundus
Flexor digitorium profundus is deep to superficialis
Flexor pollicis tendon is lateral to flexor digitorium tendons
Median nerve is anterior to all tendons

Question 6

How are the tendons in the carpal tunnel protected?

Answer 6

Synovial sheath:
Flexor pollicis longus has its own synovial sheath
Flexor digitorum superficialis and profundus share a common synovial sheath