Hand and Wrist

Question 1

What forms the flexor retinaculum?

Answer 1

Thickening of the antebrachial (deep) fascia of the anterior forearm = firstly at aspect of wrist joint then deeper and distally as transverse carpal ligament

Question 2

Where does the flexor retinaculum attach laterally and medially?

Answer 2

Laterally = scaphoid/trapezoid
Medially = pisiform and hamate

Question 3

What does the flexor retinaculum prevent?

Answer 3

Bowstringing of the tendons during flexion, which would reduce muscle efficiency

Question 4

What strengthens the flexor retinaculum?

Answer 4

Distal tendon of palmaris longus (fuses with flexor retinaculum)

Question 5

What forms the carpal tunnel?

Answer 5

Carpal bones posteriorly and the flexor retinaculum anteriorly

Question 6

What are the contents of the carpal tunnel?

Answer 6

Long tendons of forearm flexor muscles (FDS, FDP, FPL) and the median nerve (enters palm via tunnel)

Question 7

What causes carpal tunnel syndrome?

Answer 7

Compression of the median nerve due to swelling in the tunnel

Question 8

Why is the palmar cutaneous branch of the median nerve spared from carpal tunnel syndrome?

Answer 8

Given off proximal to tunnel and travels superficially to reach the skin of the palm (sensation to central palm unaffected)

Question 9

What forms the superficial palmar arch?

Answer 9

Superficial palmar branch of the ulnar artery anastomoses with the superficial branch of the radial artery

Question 10

Where is the superficial palmar arch formed?

Answer 10

Immediately deep to the palmar aponeurosis

Question 11

What forms the deep palmar arch?

Answer 11

Deep branch of the radial artery anastomosing with the deep branch of the ulnar artery

Question 12

Where does the deep palmar arch lie?

Answer 12

Runs across anterior aspects of the bases of the metacarpals

Question 13

What is Dupuytren’s contracture?

Answer 13

Pathology affecting palmar fascia = causes thickening and shortening leading to fixed flexions of the ring and little fingers

Question 14

What are the four neurovascular bundles that supply each finger?

Answer 14

Medial palmar, lateral palmar, medial dorsal, lateral dorsal

Question 15

How does the ring block anaesthetic technique work?

Answer 15

Local anaesthetic deposited in ring around base of finger to block all four proper digital nerves = surgery/suturing can be performed distal to block

Question 16

What nerves innervate the dorsal hand?

Answer 16

Ulnar, median and radial nerves

Question 17

Where does the ulnar nerve supply on the dorsal hand?

Answer 17

Medial part of dorsum of hand, little finger, medial half of ring finger

Question 18

Where does the median nerve supply on the dorsal hand?

Answer 18

Skin over distal phalanges/nail beds of thumb, index finger, middle and ring fingers

Question 19

Where does the radial nerve supply on the dorsal hand?

Answer 19

Skin over anatomical snuff box, lateral part of dorsum of hand, proximal thumb, middle and ring fingers

Question 20

How many lumbricals are there?

Answer 20

Four = one for each finger

Question 21

Where do the lumbricals attach?

Answer 21

Between the FDP tendon and extensor expansion of same digit

Question 22

Where do the lumbricals span?

Answer 22

Anterior aspect of second to fifth MCP joints and then the posterior aspect of the second to fifth PIP joints

Question 23

What action do the lumbricals perform?

Answer 23

Flexion of the MCPs and extension of the PIPs

Question 24

What nerves supply the lumbricals?

Answer 24

Median two lumbricals = ulnar nerve

Lateral two lumbricals = median nerve

Question 25

What actions do the interossei perform?

Answer 25

Palmar interossei = adduct digits

Dorsal interossei = abduct digits

Question 26

What do the movements of the interossei occur in regards to?

Answer 26

The median plane of the hand which runs through the midline of the middle finger

Question 27

What nerve supplies the interossei?

Answer 27

The ulnar nerve

Question 28

What nerves innervate the palmar hand?

Answer 28

Ulnar, median and radial nerves

Question 29

Where does the ulnar nerve innervate on the palmar hand?

Answer 29

Medial part of palm, medial half of ring finger, little finger

Question 30

Where does the median nerve supply on the palmar hand?

Answer 30

Central/lateral palm, lateral half of ring finger, middle and index finger, thumb (excluding skin over base)

Question 31

Where on the palmar hand does the radial nerve supply?

Answer 31

Skin over base of thumb

Question 32

What are the fibrous digital sheaths continuous with?

Answer 32

The longitudinal digital bands of the palmar aponeurosis

Question 33

Where do the fibrous digital sheath attach?

Answer 33

To both sides of phalanges = form a secure tunnel through which the FDS, FDP and FPL tendons and their synovial sheaths travel distally

Question 34

Where do the tendons that pass through the fibrous digital sheaths attach?

Answer 34

To middle (FDS) and distal (FDP, FPL) phalanges respectively

Question 35

Where is the anatomical snuffbox?

Answer 35

Triangular depression on radial, dorsal aspect of hand

Question 36

What is tenderness of the floor of the anatomical snuffbox following trauma suggestive of?

Answer 36

Scaphoid fracture