Lecture 16

Question 1

What makes up the anatomical snuff box?

why is this important?

Answer 1

Lateral border: abductor pollicis longus and extensor pollicis brevis.

Medial border: extensor pollicis longus.

Roof: Superficial branch of the radial nerve and cephalic vein.

Floor: Scaphoid and trapezium, Distal ends of the tendons of ECRL & ECRB.

Contents: radial artery.

Question 2

Scaphoid fracture?

Answer 2

usually due to falling on an outstretched hand

might need to use an MRI to see the fracture

if treatment is delayed, non-union avascular necrosis of the proximal portion my occur

Question 3

Boxers fracture?

Answer 3

• Impaction fracture of the neck fifth metacarpal (sometimes can involve the fourth metacarpal)
• Usually comminuted
• Usually because of a direct blow with a clenched fist
against a solid surface

Question 4

Carpal tunnel?

Answer 4

The carpal tunnel is formed anteriorly at the wrist

Floor: Deep arch formed by the carpal bones
Roof: Flexor retinaculum
Contents: The tendons of FDS, FDP, FPL, and the median nerve

Question 5

Guyon’s canal?

Answer 5

Roof: palmar carpal ligament

Floor: flexor retinaculum and hypothenar muscles

Contents: ulnar nerve artery and vein

Question 6

compartments of the hand?

Answer 6

1. midpalmar (central) - contains long flexor tendons, lumbricals, and palmar arches
2. hypothenar eminence - contains three finger muscles and deep motor branch of ulnar nerve
3. Thenar eminence - contains FPL tendon and three thumb muscles (recurrent median nerve)
4. Four interosseous spaces - palmar and dorsal interosseous muscles (deep motor division of the ulnar nerve)

Question 7

Dupuytren’s contracture?

Answer 7

Flexion contracture of the hand

Thickening and contraction of the palmar aponeurosis

Nodule formation

Unable to extend fingers

Treatment:
needle aponeurotomy
surgery

Question 8

Trigger finger (stenosing tenosynovitis)

Answer 8

Fibrosis and tightening of the fibrous digital sheath of the flexor tendons at the level of the metacarpophalangeal (MCP) joint

Inflammation and nodule formation of the flexor tendons.

Triggering of the affected finger is due to tendons requiring excessive force to fully extend or flex

Question 9

The extensor hood?

Answer 9

Tendons of extensor digitorum and extensor pollicis longus expand over the proximal phalanx, makes a “hood” which then divides into a central band
and 2 lateral bands.

Serves as an attachment for:
Lumbricals
Dorsal interossei
Palmar interossei

Due to attachment, these muscles also extend at the
interphalangeal joint

Question 10

Dorsal interosseous

Answer 10

function:
abduction of the digits
extension of the digits

nerve:
deep branch of the ulnar nerve

Question 11

palmar interosseous

Answer 11

function:
adduction and extension of the digits

nerve:
deep branch of the ulnar nerve

Question 12

adductor policis

Answer 12

function:
adducts the thumb

nerve:
deep branch of the ulnar nerve