S9) The Wrist Flashcards

1
Q

What is the wrist joint?

A

The wrist joint (aka radiocarpal joint) is a synovial joint in the upper limb, marking the area of transition between the forearm and the hand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the structures forming the wrist joint?

A
  • Distally – proximal row of the carpal bones (except the pisiform)
  • Proximally – distal end of the radius and the articular disk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Does the ulna form part of the radiocarpal joint?

A

No, it articulates with the radius at the distal radioulnar joint but is prevented from articulating with the carpal bones by the articular disk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the blood supply to the wrist joint

A

Arterial supply via branches of the dorsal and palmar carpal arches, which are derived from the ulnar and radial arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the innervation of the wrist joint

A
  • Median nerve – anterior interosseous branch
  • Radial nerve – posterior interosseous branch
  • Ulnar nerve – deep and dorsal branches
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Identify the 4 ligaments which ensure the stability of the wrist joint

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the location and function of the palmar radiocarpal ligament

A
  • Location: anterior side of the hand, passes from the radius to both rows of carpal bones
  • Function: increases stability, ensures the hand follows the forearm during supination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the location and function of the dorsal radiocarpal ligament

A
  • Location: posterior side of the hand, passes from the radius to both rows of carpal bones
  • Function: increases stability of the wrist, ensures that the hand follows the forearm during pronation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the location and function of the ulnar collateral ligament

A
  • Location: runs from the ulnar styloid process to the triquetrum and pisiform
  • Function: prevents excessive medial joint displacement (in union with other collateral ligament)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the location and function of the radial collateral ligament

A
  • Location: runs from the radial styloid process to the scaphoid and trapezium
  • Function: prevents excessive lateral joint displacement (in union with other collateral ligament)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What type of joint is the wrist joint?

A

The wrist is an ellipsoid type synovial joint, allowing for movement along two axes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Identify the four different types of movement possible at the radiocarpal joint as well as the individual muscles involved

A
  • Flexion – flexor carpi ulnaris and flexor carpi radialis (assistance from the flexor digitorum superficialis)
  • Extension – extensor carpi radialis longus and brevis and extensor carpi ulnaris (assistance from the extensor digitorum)
  • Adduction – extensor carpi ulnaris and flexor carpi ulnaris
  • Abduction – abductor pollicis longus, flexor carpi radialis, extensor carpi radialis longus and brevis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the carpal tunnel?

A

The carpal tunnel is a narrow passageway on the anterior portion of the wrist, serving as the entrance to the palm for several tendons and the median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the borders of the carpal tunnel

A
  • The deep carpal arch (formed by carpal bones) forms a concave surface acting as the floor
  • The overlying superficial flexor retinaculum acts as the roof
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Identify the carpal bones forming the carpal arch laterally and medially

A
  • Lateral: scaphoid and trapezium tubercles
  • Medial: hook of hamate and pisiform
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

State the structure and function of the flexor retinaculum

A
  • Structure: thick connective tissue
  • Function: turns the carpal arch into the carpal tunnel
17
Q

State the origin and attachment of the flexor retinaculum

A
  • Origin: lateral side of carpal arch
  • Attachment: medial side of the carpal arch
18
Q

Briefly describe the contents of the carpal tunnel

A

The carpal tunnel contains a total of 9 tendons, surrounded by synovial sheaths, and the median nerve

19
Q

Identify the different tendons found in the carpal tunnel

A
  • The tendon of flexor pollicis longus
  • Four tendons of flexor digitorum profundus
  • Four tendons of flexor digitorum superficialis
20
Q

The synovial sheaths in the carpal tunnel allow free movement of the tendons.

How many are there?

A
  • 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
21
Q

Describe the course of the median nerve once it passes through the carpal tunnel

A

Median nerve divides into 2 branches: recurrent branch and palmar digital branch

22
Q

Which structures do the palmar digital and recurrent branches of the median nerve innervate respectively?

A
  • Palmar digital nerves give sensory innervation to the palmar skin and dorsal nail beds of the lateral 3½ digits and motor innervation to the lateral two lumbricals
  • Recurrent branch supplies the thenar muscle group
23
Q

What is the anatomical snuffbox?

A

The anatomical snuffbox is a triangular depression found on the lateral aspect of the dorsum of the hand, at the level of the carpal bones

24
Q

Identify the different borders of the anatomical snuffbox as well as the structures forming them

A

- Medial border: tendon of extensor pollicis longus

  • Lateral border: tendons of abductor pollicis longus and extensor pollicis brevis
  • Proximal border: styloid process of the radius
  • Floor: carpal bones; scaphoid and trapezium
  • Roof: skin
25
Q

Identify the contents of the anatomical snuffbox

A
26
Q

Where can the radial pulse be palpated?

A

The radial pulse can be palpated in some individuals by placing two fingers on the proximal portion of the anatomical snuffbox

27
Q

What is De Quervain’s tenosynovitis?

A
  • De Quervain’s tenosynovitis is a painful condition involving the inflammation of tendons on the side of the wrist at the base of the thumb
  • These tendons include the extensor pollicis brevis and the abductor pollicis longus tendons, which extend the joints of the thumb
28
Q

How do we test for De Quervain’s tendosynovitis?

A

Finkelstein’s Test:

  • Thumb is flexed across the palm and the fingers are then wrapped around it, the the wrist is passively adducted
  • This causes a disproportionate amount of pain over the radial styloid on the affected side
29
Q

What is Carpal tunnel syndrome?

A

- Carpal tunnel syndrome is a condition involving the compression of the median nerve due to thickened ligaments and tendon sheaths

  • It presents with numbness, tingling and pain along the distribution of the median nerve
30
Q

Describe the onset of the symptoms of Carpal tunnel syndrome

A

Sensations usually develop gradually and start off being worse during the night (diurnal variation of cortisol)

31
Q

How do we test for carpal tunnel syndrome?

A
  • 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
32
Q

What is Guyon’s canal syndrome?

A

- Guyon’s canal syndrome is a clinical condition caused by the entrapment of the ulnar nerve in the Guyon canal as it passes through the wrist

  • It presents with paraesthesia in the ring and little fingers before progressing to a loss of sensation and/or impaired motor function of the intrinsic muscles of the hand
33
Q

Where is Guyon’s canal syndrome found?

A

Ulnar tunnel syndrome is commonly seen in regular cyclists due to prolonged pressure of the Guyon’s canal against bicycle handlebars