L5.1 Wrist & Hand, bones & muscles

Question 1

How does the fracture of hook of hamate occur?

Answer 1

Aka ulnar canal syndrome or handlebar neuropathy - it occurs during actions requiring the palm (e.g. rowing, raquet sports, bicycling). It leads to compression of ulnar nerve and artery, where the ulnar nerve innervates the intrinsic hand muscles.

Question 2

Which metacarpals are likely to fracture?

Answer 2

1st - from FOOSH and 5th from contact sports e.g. boxing

Question 3

What does palmaris brevis do?

Answer 3

Similar to palmar aponeurosis, it tightens palmar side of hand

Question 4

Dupuytrens contracture of palmar fascia

Answer 4

Idiopathic condition. Thickening and shrinking of palmar fascia, affecting ring and little finger.

Question 5

Where does the flexor retinaculum attach to?

Answer 5

Trapezium and scaphoid (laterally)

Hamate and pisiform (medially)

Question 6

What forms roof of carpal tunnel? How many tendons and what structures go through the carpal tunnel? What structure attach to carpal tunnel?

Answer 6

Roof: Flexor retinaculum
Floor: carpal bones
Contents:
9 tendons, FDS (x4), FDP (x4), FPL (x1), median nerve, synovial sheaths

Question 7

Proximal end of carpal tunnel is identified by?

Answer 7

Distal wrist crease

Question 8

Structures superficial to flexor retinaculum?

Answer 8

PL tendon
Ulnar a, ulnar n
Radial a - superficial branch
Palmar cutaneous branch of median n.

*FCU tendon lies well medial

Question 9

What is found within roof of carpal tunnel?

Answer 9

FCR