Musculoskeletal: Anatomy - Wrist and hand

Question 1

List the bones of the carpus (counter-clockwise beginning at scaphoid)

Answer 1

So Long The-Pinky (lateral to medial proximal: Scaphoid, Lunate, Triquetrum-Pisiform)
Here Comes The Thumb (medial to lateral distal: Hamate, Capitate, Trapezoid, Trapezi-thumb)

Question 2

Which carpal bones have tubercles?

Answer 2

Scaphoid on palmar aspect
Trapezium on palmar aspect

Question 3

What are the defining features of the scaphoid?

Answer 3

Scaphoid tubercle on palmar aspect: gives attachment to transverse carpal ligament
Waist between proximal and distal portions: common site of fracture

Question 4

Which carpal bones articulate with the distal radius?

Answer 4

Scaphoid, lunate

Question 5

Explain the meanings of the carpal bone names (gives an indication of shape)

Answer 5

Scaphoid: skiff
Lunate: moon
Triquetrum: three-cornered (pyramidal)
Pisiform: pea
Hamate: little hook (wedge-shaped with hooked process)
Capitate: head
Trapezoid: wedge (resembles trapezium)
Trapezium: table (four-sided)

Question 6

Describe the position of the pisiform

Answer 6

Lies on the palmar surface of the triquetrum

Question 7

What bone articulates with the articular disc of the distal radio-ulnar joint?

Answer 7

Triquetrum

Question 8

What is the defining feature of hamate?

Answer 8

Hook of hamate: extends anteriorly and forms medial border of the carpal tunnel

Question 9

What does trapezium articulate with?

Answer 9

1st and 2nd metacarpals
Trapezoid
Scaphoid

Question 10

What does trapezoid articulate with?

Answer 10

2nd metacarpal
Trapezium
Capitate
Scaphoid

Question 11

What does capitate articulate with?

Answer 11

3rd metacarpal primarily
Trapezoid
Hamate
Lunate
Scaphoid

Question 12

What does hamate articulate with?

Answer 12

4th and 5th metacarpals
Capitate
Triquetrum

Question 13

What does scaphoid articulate with

Answer 13

Distal radius
Trapezium
Trapezoid
Capitate

Question 14

What is the most frequently fractured carpal bone?

Answer 14

Scaphoid

Question 15

What is the typical mechanism of scaphoid fracture?

Answer 15

FOOSH with hand abducted

Question 16

Why is scaphoid fracture more obviously on XR at 10-14 days post-injury?

Answer 16

Bony resoprtion has taken place

Question 17

How long does scaphoid fracture union take?

Answer 17

May take 3 months due to poor blood supply to proximal scaphoid

Question 18

What is a possible complication of scaphoid fracture?

Answer 18

Avascular necrosis of proximal fragment

Question 19

What are the possible complications of hamate fracture?

Answer 19

Nonunion due to traction by attached hypothenar muscles
Ulnar nerve injury causing decreased grip strength
Ulnar artery damage

Question 20

What is a boxer’s fracture? What is the mechanism?

Answer 20

Fracture of the 5th metacarpal
Punch with closed and abducted fist

Question 21

By what age are all ossification centres of the carpal bones visible?

Answer 21

11

Question 22

What distinguishes the third metacarpal?

Answer 22

Styloid process on lateral base