Hand

Question 1

Which joint gives the thumb its mobility?

Answer 1

Trapeziometacarpal joint

Question 2

Radiocarpal joint is between which two carpal bones and which arm bone?

Answer 2

Radius and scaphoid, lunate

Question 3

Which part of what bone is important attachment for transverse carpal ligament?

Answer 3

Hamulus (hook of HAMATE bone)

Question 4

Colles fracture

Answer 4

Most common fracture of forearm, distal radial fracture when you trip and fall on one hand – “dinner fork” deformity with bends first ventral proximal then distal to wrist

Question 5

Reverse Colles fracture (Smith’s fracture)

Answer 5

Distal radius is displaced anteriorly

Question 6

Scaphoid fracture

Answer 6

Most commonly fractured carpal bone caused by falling on outstretched hand, difficult to see with radiograph, can lead to necrosis of proximal part of scaphoid by disrupting blood supply

Question 7

Movements of the thumb

Answer 7

Extension and flexion – in and out towards and away palm

Adduction and abduction – up and down towards and away from fingers

Question 8

Palmar aponeurosis

Answer 8

Tendon of palmaris longus attaches here

Question 9

2 main compartments of the hand and their muscles

Answer 9

Thenar eminence (abductor pollicis brevis, flexor pollicis brevis, opponens pollicis) and hypothenar eminence (abductor digiti minimi, flexor digiti minimi, opponens digiti minimi)

Question 10

Innervation of hypothenar eminence muscles

Answer 10

Deep branch of ulnar n

Question 11

Innervation of thenar eminence muscles

Answer 11

Recurrent branch of median n EXCEPT deep head of flexor pollicis brevis, which is innervated by ulnar n

Question 12

Adductor pollicis: action

Answer 12

Bring thumb back in line with fingers (adduction)

Question 13

Adductor pollicis: innervation

Answer 13

Ulnar n

Question 14

Lumbricals: attachments

Answer 14

Origin: tendon of flexor digitorum profundus
Insertion: extensor expansion

Question 15

Lumbricals: action

Answer 15

Flex MCP joints, extend PIP and DIP joints

Question 16

Lumbricals: innervation

Answer 16

Lateral two lumbricals (I and II) = median n

Medial two lumbricals (III and IV) = ulnar n

Question 17

Extensor expansion

Answer 17

Allows lumbricals to both flex fingers and keep them extended at PIPs and DIPs

Question 18

Dorsal interossei muscles

Answer 18

DAB – abduct – 4 of them because middle finger moves both ways and needs 2 (lateral digits have their own)

Question 19

Palmar interossei muscles

Answer 19

PAD – adduct – 3rd digit can’t adduct so it doesn’t need one, thumb has its own

Question 20

Which artery sits in the anatomical snuffbox?

Answer 20

Radial artery

Question 21

Branches of ulnar artery in hand

Answer 21

Superficial palmar arch, common palmar digital aa, proper palmar digital aa, deep branch

Question 22

Branches of radial artery in hand

Answer 22

Princeps pollicis a, radial indicis a, deep palmar arch, palmar metacarpal aa

Question 23

Palmar anastomoses (2)

Answer 23

Ulnar artery > superficial palmar arch > superficial palmar branch of radial a > radial a
Radial artery > deep palmar arch > deep palmar branch of ulnar a > ulnar a
CAN TEST WITH ALLEN’S TEST

Question 24

Branches of median n in hand

Answer 24

Goes into carpal tunnel then breaks into common palmar digital nerves (lumbricals), proper palmar digital nerves (lumbricals), and recurrent branch of median n (motor to thenar eminence, NO LUMBRICALS)

Question 25

Branches of ulnar n in hand

Answer 25

In ulnar canal -- deep (motor to hand) and superficial branch (sensory innervation), common and proper palmar digital nerves

Question 26

Ulnar canal

Answer 26

Narrow passage between pisiform and hook of hamate (hamulus) where ulnar n passes, common site of ulnar nerve compression (like cyclists) -- handlebar neuropathy

Question 27

Ulnar claw

Answer 27

Damage at medial arm or cubital tunnel, clawing of digits 4 and 5 because lumbrical function is gone, inability to make tight fist because of loss of intrinsic hand muscles (causes extension at MCP, joint and flexion at IP joints, wasting of first dorsal interosseous)

Question 28

Cutaneous innervation: ulnar

Answer 28

Medial aspect of palm and dorsum of hand

Question 29

Cutaneous innervation: radial

Answer 29

Lateral aspect of dorsum of hand

Question 30

Cutaneous innervation: median

Answer 30

Lateral aspect of palm of hand

Question 31

Median nerve innervation of hand

Answer 31

``` 1/2 LOAF 1/2 L: lateral two lumbricals O: opponens pollicis A: abductor pollicis brevis F: flexor pollicis brevis ADDUCTOR POLLICIS IS INNERVATED BY ULNAR N ```

Question 32

Flexor retinaculum

Answer 32

Attached to carpals (pisiform and hamate --> scaphoid and trapezium), covers flexors to form CARPAL TUNNEL

Question 33

Carpal tunnel syndrome

Answer 33

Median nerve compression that can lead to loss of sensation and tingling in digits 1-3, loss of motor to thenar eminence via recurrent branch of median n, loss of motor to lateral 2 lumbricals, thumb laterally rotated and adducted and opposition is not possible

Question 34

Hand of the benediction

Answer 34

Loss of median nerve at elbow or above, causes inability to flex MCP and IP joints of digits 1-3