The Forearm/Wrist/Hand Flashcards Preview

Musculoskeletal > The Forearm/Wrist/Hand > Flashcards

Flashcards in The Forearm/Wrist/Hand Deck (45):
1

Which three muscles are responsible for thumb extension?

EPL
EPB
APL

2

Which two muscles are responsible for thumb flexion?

FPL
FPB

3

Which two muscles are responsible for thumb abduction?

AbPL
AbPB

4

Which two muscles are responsible for thumb adduction?

Ad P
1st dorsal interosseous

5

Which muscles compose the thenar eminence of the hand?

OpP
AbPB
FPB
AdP

6

Which muscles compose the hypothenar eminence of the hand?

AbDM
FDMB
Opponens digiti

7

Which muscles of the hand does the median nerve innervate?

LLOAF

First two lateral lumbricals
Opponens Pollicis
AbPB
FPB

8

What is the sensory distribution of the median nerve in the hand?

Lateral 3.5 fingers palmar aspect

Tips of 3.5 fingers dorsal aspect

9

Which muscles of the hand does the ulnar nerve innervate?

All intrinsic muscles (except LLOAF)

10

What is the sensory distribution of the ulnar nerve in the hand?

Palmar and dorsal aspects of 1.5 medial digits

11

Describe the key landmarks of the anatomical snuffbox.

Anterior boundary: Tendons of APL and EPB

Posterior boundary: Tendon of EPL

Floor: Radial artery, scaphoid, trapezium

12

Which muscles are involved in wrist flexion?

FCR
FCU
Assisted by: flexors of fingers and thumb, palmaris longus, APL

13

Which muscles are involved in wrist extension?

ECRL
ECRB
ECU
Assisted by: extensors of fingers and thumb

14

Which muscles are involved in wrist abduction?

APL
FCR
ECRL
ECRB

15

Which muscles are involved in wrist adduction?

ECU
FCU

16

What are the contents of the carpal tunnel?

FDP (x4 tendons)
FDS (x4 tendons)
FPL (x1 tendon)

Median nerve

17

What is mallet finger and how does it occur?

DIP joint forced into extreme flexion (hyperflexion) - can occur from either extensor tendon rupture at base of distal phalanx (no bony involvement) or avulsion injury

18

What is involved in the management of mallet finger? (2)

1. Closed injuries treated with immobilisation splint with DIP joint in extension or hyperextension FULL TIME for 8 weeks, can be graded to night splinting if appropriate thereafter. Important to keep finger in extension in between/during splint changes, and watch out for skin breakdown.

2. Surgery reserved for severe injury (e.g. volar subluxation of distal phalanx, injuries failing conservative management etc.)

19

What is trigger finger and what can it be caused by? (4)

aka stenosing tenosynovitis

Inflammation of flexor tendon sheath of finger/thumb causing pain and swelling to occur proximally at MCP joint (+/- nodule formation) and prevents smooth gliding under A1 pulley = locking of thumb or finger in flexion primarily



Aetiology: idiopathic or assoc. w/ RA, diabetes, hypothyroidism and gout

20

How is trigger finger diagnosed?

Primarily clinical diagnosis

21

How is trigger finger managed? (2)

- reduce swelling and inflammation by immobilisation for 4-6 weeks (+/- glucocorticoid injection if refractory) OR local glucocorticoid injection straight up if locking is severe
- avoid gripping, grasping etc.
- panadol and ice for pain
- on resolution of acute symptoms, gentle stretching exercises (extension)

2. Surgical release of A1 pulley when locking and tenosynovitis persist despite two consecutive local glucocorticoid injection

22

What is carpal tunnel syndrome?

Median nerve compression at the level of the flexor retinaculum

23

What is the aetiology of carpal tunnel syndrome

Myxoedema
Oedema
Diabetes
Idiopathic
Acromegaly
Neoplasm
Trauma
Rheumatoid arthritis
Amyloidosis
Pregnancy

24

List 6 clinical features of carpal tunnel syndrome

1. Sensory loss in median nerve distribution i.e. radial 3.5 digits

2. Classically, patient awakened at night with numb/painful hand, relieved by shaking, dangling, rubbing

3. Discriminative touch often lost first, with decreased light touch and 2-point discrimination

4. Advanced cases: thenar wasting, weakness

5. +/- Tinel's sign (tingling sensation on percussion of nerve)

6. +/- Phalen's sign (wrist flexion induces symptoms)

25

How is carpal tunnel diagnosed?

CLINICALLY

NCV and EMG may confirm, but do not exclude, the diagnosis

26

How is carpal tunnel syndrome managed? (3)

1. Wrist splinting in neutral position - usually at night but can be worn continuously esp. when repetitive wrist motion required

2. Medical: NSAIDs, local corticosteroids, oral corticosteroids

3. Surgical decompression - indicate if symptoms are intolerable and/or unresponsive to conservative measures

27

What is the most common carpal bone injured?

Scaphoid

28

Describe the type of injury seen in a scaphoid fracture.

Most commonly a transverse fracture through the waist of scaphoid, but can be distal or proximal fracture also

A larger percentage of proximal fractures result in non-union or AVN due to distribution of blood supply

29

Which clinical feature is most sensitive for scaphoid injury?

Tenderness over anatomical snuffbox

30

How is a suspected scaphoid fracture investigated?

1. X-rays: AP, lateral ,scaphoid view *wrist extension and ulnar deviation)
2. If X-ray negative but clinical features present, splint or plaster should be applied For two weeks
3. After two weeks, a second X-ray is taken. If still no abnormalities, MRI or CT scan.

31

How is an undisplaced scaphoid fracture managed? (3)

1. No reduction required
2. Cast: upper foreatm to just short of MCPs of fingers, incorporation proximal phalanx of thumb ('holding glass' position) for 8 weeks
3. After 8 weeks,remove plaster and examine wrist clinically and radiologically - if all good, wrist left free

32

How is a displaced scaphoid fracture managed?

ORIF (with compression screw)

33

List 3 complications of scaphoid fractures.

1. AVN due to distal to proximal supply
2. Non-union
3. OA secondary to AVN or non-union

34

What is a nightstick fracture and how does it occur?

Isolated fracture of ulna without dislocation of radial head - from direct blow to forearm (e.g. holding arm up to protect face)

35

How is a nightstick fracture managed? (2)

1. Non-displaced - below elbow cast (x10 d) followed by forearm brace (~8 weeks)

2. Displaced - ORIF if more than 50% displaced

36

What is a Galeazzi fracture and how does it occur?

Fracture of the distal radial shaft with disruption of the distal radio-ulnar joint and associated ulnar dislocation.

FOOSH with some rotational force

37

What is the piano-key sign?

Seen in a Galeazzi fracture - unstable ulna can be ballotted by holding patient's forearm pronated and pushing sharply on prominent head of ulna

38

How is a Galeazzi fracture managed? (3)

1. ORIF of radius
2. If DRUJ is stable and reducible, splint for 48h with early ROM encouraged
3. If DRUJ is unstable, ORIF or percutaneous pinning with long arm cast in supination x 6 weeks

39

What is a Colles' fracture and in whom does it usually occur?

Transverse distal radius fracture with dorsal displacement +/- ulnar styloid fracture

Most common fracture in those >40 years especially women due to post-menopausal osteoporosis - mechanism = FOOSH

40

What is the typical clinical feature seen in a Colles' fracture?

'Dinner fork deformity' - prominence of back of wrist and depression in front

41

How is an undisplaced Colles' fracture managed? (3)

1. Dorsal splint for a few days until swelling resolves, then cast is completed

2. X-rays at 2 weeks - surgery if fracture has slipped

3. If not, cast removed at 4 weeks to allow mobilisation

42

How is a displaced Colles' fracture managed? (3)

1.Closed reduction under anaesthesia (Haematoma, Bier's or axillary block)

2. Position checked by X-ray and dorsal plaster slab applied

3. X-rays retaken at 7-10 days - if re-displaced - re-manipulation/internal fixation in patients with high functional demands
- in older people - modest degrees of displacement accepted

43

What is a Smith's fracture and how does it occur?

Volar displacement of the distal radius (i.e. distal fragment displaced anteriorly) aka reverse Colles' fracture

Can occur after fall onto the back of the flexed hand causing 'garden spade' deformity

44

How is a Smith's fracture managed?

Usually unstable and needs ORIF - closed reduction under block then long-arm cast in supination x 6 weeks

45

List some complications of wrist fractures. (3 early vs 5 late)

Early
1. Compartment syndrome
2. EPL tendon rupture
3. Acute carpal tunnel syndrome

Late
1. Malunion, radial shortening
2. Post-traumatic arthritis
3. Carpal tunnel syndrome
4. CRPS/RSD
5. 'Shoulder-hand syndrome' - trophic/vasomotor changes/ reflex sympathetic dystrophic characterised by pain and stiffness in shoulder followed by swelling/stiffening of hand and fingers