L8 Anatomy of the hand

Question 1

Hand - bone groups

Answer 1

• Carpals
• Metacarpals
• Phalanges

Question 2

Carpal bones

Answer 2

• Scaphoid
• Lunate
• Triquetral/triquetrium
• Pisiform
• Trapezium
• Trapezoid
• Capitate
• Hamate

Question 3

Joints of the hand

Answer 3

• Wrist (radiocarpal)
• Midcarpal/intercarpal
• Carpometacarpal (saddle joint)
• Metacarpophalangreal
• Interphalangeal

Question 4

Wrist(radiocarpal) joint

Answer 4

• Between radius/disc and first carpal row

- Reinforced by ligaments

Question 5

Ligaments that reinforce the wrist(radiocarpal) joint

Answer 5

• Ulnar and radial collateral ligaments (limits abduction/adduction)
• Ligaments on the palmar/dorsal surfaces (limits extension/flexion)

Question 6

Purpose of radial styloid process

Answer 6

• Limits range of abduction

Question 7

What does the wrist joint allow for

Answer 7

• Flexion/extension
• Abduction/adduction
• Circumduction

Question 8

Carpometacarpal joints

Answer 8

• Plane joints (limited movement)

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

Question 9

Movements of the thumb

Answer 9

• Extension
• Flexion
• Abduction
• Adduction
• Opposition
• Reposition

Question 10

Metacarpophalangeal joints

Answer 10

Condylar joints - flexion/extension, abduction/adduction

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

Question 11

Interphalangeal joints

Answer 11

• Hinge joints
• Flexion/extension
• Proximal and distal interphalangeal joints

Question 12

Palmar aponeurosis

Answer 12

• Thickened deep fascia
• Triangular
• Continuous with palmaris longus
• Consists of longitudinal and transverse fibres

Question 13

Clinical relevance of palmar aponeurosis

Answer 13

• Dupuytren’s contracture

Question 14

Long flexor tendons to digits

Answer 14

• From muscles in anterior forearm

- Pass through carpal tunnel

Question 15

Flexor retinaculum

Answer 15

• Transverse carpal ligament

- Prevents bowing of tendons

Question 16

Long flexor tendons associated with each digit

Answer 16

• Flexor digitorum superficialis (d2-5)
• Flexor digitorum profundus (d2-5)
• Flexor pollicis longus (d1)

Question 17

Flexor tendon insertions

Answer 17

• Alternating fibrous annular (A1-A5 pulley’s) and cruciate ligaments

Question 18

Where does flexor digitorum profundus insert

Answer 18

• To base of distal phalanx

Question 19

Where does flexor digitorum superficialis insert

Answer 19

• To base of middle phalanx

- Note the vinculae (attach tendons to phalanges)

Question 20

Long extensor tendons to digits

Answer 20

From muscles in posterior forearm

Extensor digitorum, indicis and digit minimi –> d2-5

Extensor pollicis longus, extensor pollicis brevis and abductor pollicis longus –> d1

Question 21

Extensor tendons that go through the anatomical snuff box

Answer 21

Abductor pollicis longus - to base of 1st metacarpal

Extensor pollicis brevis - to base of proximal phalanx

Extensor pollicis longus - to base of distal phalanx

Question 22

Which artery goes through the anatomical snuff box

Answer 22

• Radial artery

Question 23

Extensor digitorum insertion

Answer 23

• Medial band (into middle phalanx)

- Lateral band(into distal phalanx)

Question 24

Muscles that insert into the extensor hoods

Answer 24

• Lumbricals and interossei insert into the extensor hoods

Question 25

Lumbricals

Answer 25

Link flexor to extensor tendons - Extend interphalangeal joints and flex MCP joints - Precision grip (hold pen/pinch)

Question 26

Palmar interossei

Answer 26

Interossei sit between the metacarpals

Question 27

Where do the palmar interossei muscles run from

Answer 27

3 palmar interossei | - Run from the metacarpals to the extensor hoods (d2, d4, d5)

Question 28

Role of palmar interossei muscles

Answer 28

- Palmar adduct (PAD) MCP joints - relative to middle finger (D3) - No palmar interossei for D1(performed by adductor pollicis muscle) or D3

Question 29

Where do the dorsal interossei run from

Answer 29

4 dorsal interossei | - Run from metacarpals to extensor hoods d2, d3(x2), d4

Question 30

Action of dorsal interossei

Answer 30

- Dorsal abduct (DAB) MCP joints - relative to middle finger (D3) - No dorsal interossei for D1 or D5 (performed by thenar and hypothenar muscles)

Question 31

Role of thenar and hypothenar muscles

Answer 31

Thenar muscles - fine movements of the thumb (d1) Hypothenar muscles - fine movements of the little finger (d5)

Question 32

Origin of thenar and hypothenar muscles

Answer 32

Thenar muscles - fine movements of the thumb (d1) Hypothenar muscles - fine movements of the little finger (d5)

Question 33

Thenar muscles

Answer 33

1. Opponens pollicis (deepest) - inserts into first metcarpal 2. Abductor pollicis brevis 3. Flexor pollicis brevis - inserts into proximal phalanx

Question 34

Hypothenar muscles

Answer 34

1. Opponens digiti minimi (deepest) - inserts into fifth metacarpal 2. Abductor digiti minimi 3. Flexor digiti minimi - inserts into proximal phalanx

Question 35

Adduction of the thumb

Answer 35

- Adductor pollicis - Oblique head from the base of 2nd and 3rd metacarpal + carpal bones into proximal phalanx - Transverse head -from the 3rd metacarpal into the proximal phalanx - Deep to thenar muscles

Question 36

Blood supply to the hand

Answer 36

Radial artery - towards dorsal surface Ulnar artery - Form complex anastomosis in hand so that blood can reach all parts in hand positions

Question 37

Deep palmar arch

Answer 37

- Below long flexor tendons - Radial artery enters between first dorsal interosseous muscle and floor of anatomical snuff box - D1 and 1/2 D2 = mainly radial artery

Question 38

Superficial palmar arch

Answer 38

- Above long flexor tendons - Ulnar artery - Lead to 3 common palmar digital arteries and proper palmar digital arteries - 1/2 d2 to d5 = mainly ulnar artery

Question 39

Which nerve passes through carpal tunnel

Answer 39

Median

Question 40

Branches of median nerve in hand

Answer 40

- Recurrent branch --> thenar muscles | - Digital nerves --> lateral 2 lumbricals + sensory d1 to 1/2 d4

Question 41

Ulnar nerve branches in hand

Answer 41

Deep branch - hypothenar muscles, interossei, medial 2 lumbricals, adductor pollicis Superficial branch - sensory 1/2 d4 and d5

Question 42

ulnar nerve clinical relevance - hand

Answer 42

clawed hand