Upper limb 4: Wrist and hand

Question 1

What are the 4 proximal carpal bones of the hand?

Answer 1

Scaphoid
Lunate
Triquetrum
Pisiform

Question 2

What are the 4 distal carpal bones of the hand?

Answer 2

Trapezium
Trapezoid
Capitate
Hamate

Question 3

Which carpal bone is a sesamoid bone?

Answer 3

Pisiform

Question 4

What are the attachment points of the medial collateral ligament of the wrist?

Answer 4

Ulnar styloid + triquetrum

Question 5

What are the attachment points of the lateral collateral ligament of the wrist?

Answer 5

Radial styloid + scaphoid

Question 6

Which carpal bone is susceptible to fracture in a FOOSH injury?

Answer 6

Scaphoid

Question 7

A Bennett’s fracture is a fracture of what?

Answer 7

The base of the thumb’s metacarpal bone

Question 8

A Colle’s fracture is a fracture of what?

Answer 8

Distal end of radius

Question 9

What sort of displacement would be seen in a Colle’s fracture?

Answer 9

Dorsal displacement of free floating distal wrist / hand (dinner fork)

Question 10

What sort of displacement would be seen in a Smith’s fracture?

Answer 10

Ventral displacement of free floating distal wrist / hand

Question 11

What are the 2 lateral and 1 medial borders of the snuffbox?

Answer 11

Abductor pollicis longus (APL)
Extensor pollicis brevis (EPB)

Extensor pollicis longus (EPL)

Question 12

Tenderness in the snuffbox can indicate a fracture to which bone?

Answer 12

Scaphoid

Question 13

Which structure passes over the snuffbox?

Answer 13

Cephalic vein

Question 14

Which artery and nerve pass through the snuffbox?

Answer 14

Radial artery

Superficial radial nerve

Question 15

The palmar aponeurosis is continuous with the tendon of which muscle?

Answer 15

Palmaris longus

Question 16

Which 2 roots of the brachial plexus innervate the hand muscles?

Answer 16

C8 + T1

Question 17

Most of the hand muscles are innervated by which nerve?

What are the exceptions?

Answer 17

Ulnar nerve

Thenar muscles + digits 2 + 3 - median nerve

Question 18

Which muscles adduct the hand?

Answer 18

Palmar interossei muscles

Question 19

Which muscles abduct the hand?

Answer 19

Dorsal interossei muscles

Question 20

What are the 2 functions of the lumbricals?

Answer 20

Flexion of MCP joints

Extension of PIP + DIP joints

Question 21

What is the innervation of lumbricals 1 + 2?

Answer 21

Median nerve

Question 22

What is the innervation of lumbricals 3 + 4?

Answer 22

Ulnar nerve

Question 23

Describe the ulnar nerve paradox.

Answer 23

More severe clawing of hand when ulnar nerve lesion is more distal - usually it would be proximal as more structures are affected

When the lesion is distal, the flexor digitorum profundus (flexes DIP of digits 4 + 5) is still intact, but the lumbricals are paralysed, so there is severe claw hand

But, when the lesion is proximal, both the lumbricals and FDP are paralysed, so there’s less flexion force at DIP joints

Question 24

A lesion to which nerve will present with froment’s sign?

Answer 24

Ulnar nerve

Question 25

What is a Froment's sign? Which nerve is damaged?

Answer 25

Loss of adductor pollicis leads to excess thumb flexion whilst pinching Ulnar nerve

Question 26

Which 4 bones border the carpal tunnel?

Answer 26

Scaphoid Trapezium Pisiform Hook of hamate

Question 27

Which tendons and nerve sits in the carpal tunnel?

Answer 27

Tendons of FDP Tendons of FDS Tendon of FPL Median nerve

Question 28

Why is palmar sensation from the median nerve not affected by carpal tunnel syndrome?

Answer 28

The palmar (cutaneous) branch of the median nerve branches off and runs superficial to the tunnel

Question 29

Which 2 tests check for a median nerve lesion?

Answer 29

Tinel's test Phalen's test

Question 30

What is carpal tunnel release?

Answer 30

Partial or complete surgical division of flexor retinaculum

Question 31

Which test can be used to check for collateral blood supply in the hand?

Answer 31

Allen's test