8. Anatomy of the hand

Question 1

Skeleton of hand

Answer 1

Carpals
Metacarpals
Phalanges

Question 2

Carpal bone arrangement

Answer 2

2 rows: distal and proximal, form carpal arch

Question 3

Carpal bones proximal row:

Answer 3

Proximal row:
Pisiform - in FCU
Triquetral - triangle shaped
Lunate - moon shaped
Scaphoid - largest

Question 4

Carpal bones distal row

Answer 4

Trapezium - forms saddle joint for thumb
Trapezoid
Capitate - skull-looking
Hamate - looks like hammer. Has hook of hamate

Question 5

Clinical aspect of carpal bones?

Answer 5

Fracture of scaphoid is common. Slow recovery, as poor blood supply to proximal part - avascular necrosis

Question 6

Joints of hand

Answer 6

Wrist bones - radiocarpal joints

Micarpal/intercarpal - not a lot of movement

Carpometacarpal joints

saddle joint - thumb one

interphalangeal joint - in fingers themselves, 1 in thumb, 2 in rest

Question 7

Wrist (radiocarpal joint)

Answer 7

Between radius/disc and first carpal row
Reinforced by ligaments

Ulnar and radial collateral ligaments
Ligaments on the palmar/dorsal surfaces

Question 8

Ulnar and radial collateral ligaments

Answer 8

limits abduction/adduction

Question 9

Ligaments on the palmar/dorsal surfaces

Answer 9

limits extension/flexion

Question 10

Radial styloid process

Answer 10

limits range of abduction

Question 11

Carpometacarpal joints

Answer 11

Plane joints - Limited movement

Except for the saddle joint (between trapezium and d1)
- Enables opposition

Question 12

Movements of the thumb

Answer 12

Movements of the thumb: extension, flexion, abduction, adduction, opposition, reposition

Question 13

Metacarpophalangeal joints

Answer 13

Condylar joints
Flexion/extension
Abduction/adduction

Deep transverse metacarpal ligaments unifies metacarpals, not between digit 1 and 2

Question 14

Interphalangeal joints

Answer 14

Hinge joints
Flexion/extension

Proximal interphalangeal joints (PIPs)
and
Distal interphalangeal joints (DIPs)

Question 15

palmar aponeurosis

Answer 15

Thickened deep fascia
Triangular
Continuous with palmaris longus

Clinical – Dupuytren’s contracture

Question 16

Long flexor tendons to digits

Answer 16

From muscles in anterior forearm

Pass through carpal tunnel

Question 17

Flexor digitorum superficialis

Answer 17

d2-d5

Question 18

Flexor digitorum profundus

Answer 18

d2-d5

Question 19

Flexor pollicis longus

Answer 19

d1

Question 20

Flexor retinaculum

Answer 20

aka transverse carpal ligament

prevents bowing of tendons

Question 21

Nerve passing through carpal tunnel

Answer 21

Median nerve

Question 22

What surrounds the tendons?

Answer 22

synovial sheaths

Question 23

Flexor tendon insertions

Answer 23

Flexor digitorum profundus To base of distal phalanx

Flexor digitorum superficialis
To base of middle phalanx

Question 24

What are vinculae?

Answer 24

Attach tendons to phalanges

Question 25

What surrounds the tendons?

Answer 25

Synovial sheath surrounded by fibrous digital sheath Alternating fibrous annular (A1-A5 pulley’s) and cruciate ligaments

Question 26

Long extensor tendons to digits

Answer 26

From muscles in posterior forearm D2-D5: Extensor digitorum Extensor indicis Extensor digit minimi D1: Extensor pollicis longus Extensor pollicis brevis Abductor pollicis longus

Question 27

Anatomical snuffbox

Answer 27

``` Anterior: abductor policis longus Lateral: extensor policis brevis Medial: extensor policis longus Floor: scaphoid bone and trapezium Passing through anatomical space: radial artery ```

Question 28

Extensor digitorum insertion

Answer 28

into both middle phalanx (middle band of extensor digitorum) | and distal phalanx (lateral band)

Question 29

Extensor hoods

Answer 29

Lumbricals and interossei insert into the extensor hoods

Question 30

Lumbricals

Answer 30

Link flexor to extensor tendons - Extend interphalangeal joints and flex MCP joints - Precision grip (hold pen / pinch) Flexor digitorum profundus inserts into extensor hood

Question 31

palmar interossei

Answer 31

Interossei sit between the metacarpals 3 Palmar interossei Metacarpals -> Extensor hoods (d2, d4 ,d5) ``` Palmar adduct (PAD) MCP joints Relative to middle finger (D3) ``` No palmar interossei for D1 (performed by adductor pollicis muscle) or D3

Question 32

Dorsal interossei

Answer 32

4 Dorsal interossei Metacarpals -> Extensor hoods d2, d3 (x2) ,d4 ``` Dorsal abduct (DAB) MCP joints Relative to middle finger (D3) ``` No dorsal interossei for D1 or D5 (performed by thenar and hypothenar muscles)

Question 33

Thenar and hypothenar muscles

Answer 33

thenar muscles - fine movements of the thumb (d1) hypothenar muscles - fine movements of the little finger (d5)

Question 34

Thenar muscles

Answer 34

Three muscles: 1. Opponens pollicis (into first metacarpal) 2. Abductor pollicis brevis 3. Flexor pollicis brevis (both into proximal phalanx)

Question 35

Hypothenar muscles

Answer 35

Three muscles: 1. Opponens digiti minimi into fifth metacarpal 2. Abductor digiti minimi 3. Flexor digiti minimi both into proximal phalanx

Question 36

Adduction of the thumb

Answer 36

Adductor pollicis Oblique head Base 2nd and 3rd metacarpal + carpal bones Transverse head 3rd metacarpal both into proximal phalanx

Question 37

What forms a complex anastamosis in the hand?

Answer 37

radial artery ulnar artery form complex anastomosis in hand (So that blood can reach all parts in all hand positions)

Question 38

Where is the deep palmar arch

Answer 38

Below long flexor tendons

Question 39

What does the deep palmar arch supply?

Answer 39

D1 and 1/2 D2

Question 40

Branches of deep palmar arch

Answer 40

princeps pollicis artery to D1 | Radialis indicis artery to 1/2 of D2

Question 41

Where is superficial palmar arch?

Answer 41

above long flexor tendons

Question 42

Branches of superficial palmar arch

Answer 42

3 common palmar digital arteries | proper palmer digital arteries

Question 43

What does superficial palmar arch supply?

Answer 43

1/2 D2 to D5

Question 44

Where does median nerve pass through?

Answer 44

Carpal tunnel

Question 45

Branches of median nerve

Answer 45

Recurrent branch to thenar muscles | Digital nerves to lateral 2 lumbricals and sensory d1 to 1/2 d5

Question 46

Clinical relevance of median nerve

Answer 46

Carpal tunnel syndrome

Question 47

What does the ulnar nerve supply?

Answer 47

deep branch to hypothenar muscles, interossei, medial 2 lumbricals, adductor pollicis superficial branch to sensory 1/2 d4 and d5

Question 48

Clinical relevance of ulnar nerve

Answer 48

clawed hand