Forearm, Wrist, Hand (+muscles)

Question 1

what makes up the proximal and distal radioulnar joint

Answer 1

proximal = radial tuberosity (radius) + radial notch

distal = ulnar head(ulnar) + ulnar notch

both are synovial pivot joints

Question 2

what attaches to radial styloid process

Answer 2

brachioradialis muscle

origin = lateral, distal supercondylar ridge of humerus

Question 3

what type of joint is the interosseous membrane between radius and ulnar

Answer 3

Syndesmosis (fibrous joint)

Question 4

colles’ fracture

Answer 4

complete transverse fracture within the distal 2cm of the radius
(most common fracture of forearm)

racture results from forced dorsiflexion of the hand, usually as the result of trying to ease a fall by outstretching the upper limb

Question 5

why are forces (e.g Fall) on outstretched hand transmitted through the radius ?

Answer 5

wrist joint( =radio-carpal joint) involves only the articulation of the distal end of the RADIUS with the Scaphoid and Lunate bones.

Question 6

Why is a fracture of the scaphoid commonly associated with avascular necrosis of the PROXIMAL fragment?

Answer 6

middle and distal part of scaphoid bone receives blood supply from dorsal and palmar branches of radial artery
but neglects the proximal portion - it relies on the retrograde flow (if fractured, no retrograde flow)

Question 7

which carpal bone is a sesamoid bone

Answer 7

pisiform in the tendon flexor carpi ulnaris

Question 8

which is deeper:

palmar carpal ligament or Flexor retinaculum (transverse carpal ligament)

Answer 8

Flexor retinaculum (transverse carpal ligament)

Question 9

what nerve is within the carpal tunnel

Answer 9

median

Question 10

what kind of joint is the 1st carpometacarpal joint (thumb)

Answer 10

saddle (synovial)

Question 11

what muscles form the lateral and medial borders of antecubital fossa

Answer 11

medial border = pronator teres

lateral = brachioradialis

Question 12

superficial venous system of arm

Answer 12

dorsal venous network of hand—> basilic and cephalic veins

basilic vein travels anterior, medial side of arm and then goes deep to join with brachial vein to form axillary vein

cephalic vein travels anterior, lateral, superficial —> delta-pectoral groove

between basilica and cephalic = median cubital vein

Question 13

bicipital aponeurosis

Answer 13

found in cubital fossa

from bicep brachii tendon to antebrachial fascia (so travels inferior-medially)

used to be known as the “Grace à Dieu” fascia by the barber- surgeons

Question 14

anterior superficial muscles forearm

Answer 14

• pronator teres
• flexor carpi radialis
• palmaris longus
• flexor carpi ulnaris

Question 15

anterior intermediate muscles of forearm:

Answer 15

-flexor digitorum superficialis

Question 16

anterior deep muscles forearm

Answer 16

• flexor pollicis longus
• flexor digitorum profundus
• pronator quadratus

Question 17

borders of anatomical snuffbox

Answer 17

Medial border = extensor pollicis longus tendon

Lateral border = abductor pollicis longus tendon + extensor pollcis brevis

Proximal border = styloid process of radius

floor = triquetrium and scaphoid carpals

roof = skin

Question 18

posterior deep forearm muscles

Answer 18

• supinator
• abductor pollicis longus
• extensor pollicis brevis
• extensor pollicis longus
• extensor indicis

Question 19

posterior superficial forearm muscles

Answer 19

• brachia’s
• extensor carpi radialis longus
• extensor carpi radialis brevis
• extensor digitorum
• extensor digiti minimi
• extensor carpi ulnaris
• anconeus

Question 20

what superficial vein and nerve run within anatomical snuffbox

Answer 20

superficial branch of radial nerve

cephalic vein

Question 21

what is flexor retinaculum attached to

Answer 21

tubercle of trapezium —> hook of hamate/pisiform

Question 22

Which structures pass superficial and deep to the flexor retinaculum?

Answer 22

Superficial Structures:

• Ulnar nerve
• Ulnar artery
• Palmar cutaneous branch of ulnar nerve
• Palmaris longus
• Palmar cutaneous branch of median nerve

Deep Structures:

• Flexor digitorum superficialis
• Flexor digitorum profundus
• Median nerve
• Flexor pollicis longus
• Flexor carpi radialis

Question 23

blood supply in forearm and hand

Answer 23

posterolateral = radial artery

anteromedial = ulnar artery

ulnar artery also –>anterior and posterior interosseous arteries, which supply deeper structures in the forearm

radial artery travels dorsally—> superficial palmar arch—> deep palmar medially

ulnar travels anteriorly –> deep palmar –> superficially laterally

Question 24

muscles of the thenar and hypothenar eminences

Answer 24

Thenar eminence:
○ Abductor pollicis brevis
○ Flexor pollicis brevis
○ Opponens pollicis

Hypothenar eminence (OFA):
○ Opponens digiti minimi
○ Flexor digiti minimi brevis
○ Abductor digiti minimi

Question 25

lumbricals

interossei muscles of hand

Answer 25

Lumbricals – flexion at metacarpophalangeal joint + extension interphalangeal joint

• There are 4 (index = 1)
• 1&2 originate from their respective tendon of flexor digitorum profundus
• 3 - from tendons to middle and ring finger
• 4 - from tendons to ring and little finger
• They all insert on the lateral side of finger

interossei muscles are deeper:

Palmar interossei - ADDUCTION and flexion at metacarpophalangeal joint whilst simultaneously extending at interphalangeal joint

• There are 3 (index,ring and little finger)
• From palmar metacarpal to the medial base of proximal phalanx

Dorsal interossei - ABDUCTION and flexion at metacarpophalangeal joint whilst simultaneously extending

• There are 4 (index, 2 on middle and ring)
• They originate from 2 metacarpals and insert to lateral base of proximal phalanx (but for middle its on both sides)