UL2 - Osteology, joints & ligaments of the forearm, wrist and hands

Question 1

articulations that form the proximal radioulnar joint?

Answer 1

radial notch of ulna articulates with radial head proximally

Question 2

articulation that forms the distal radioulnar joint?

Answer 2

ulnar notch of radius articulates with ulnar head distally

Question 3

what type of joint is the radioulnar joint (proximal and distal)? what movement does this joint allow for?

Answer 3

synovial pivot joint

allows for rotation around a single axis - ulna remains stationary as radius rotates on top of it

Question 4

what attaches at the styloid processes of the radius & ulna?

Answer 4

styloid process of radius - where the radial collateral ligament attaches

styloid process of ulna - where the ulnar collateral ligament attaches

Question 5

interosseus membrane between the radius & ulna - what does it do?

Answer 5

• provides stability to radius and ulna, prevents separation (transfers forces)
• separates the forearm into its anterior & posterior compartments

Question 6

list the proximal carpal bones (lateral to medial)

Answer 6

scaphoid
lunate
triquetral
pisiform

Question 7

list the distal carpal bones (lateral to medial)

Answer 7

hamate
capitate
trapezoid
trapezium

Question 8

which one of the proximal carpal bones is a sesamoid bone? what does this mean?

Answer 8

pisiform: a bone that develops within tendons - pisiform bone is embedded in the flexor carpi ulnaris tendon

Question 9

articulation of bones that forms the radiocarpal/ wrist joint?

Answer 9

• (concave) distal end of the radius
• scaphoid & lunate bones directly
• indirectly with the triquetral bone via an articular disc

Question 10

what type of joint is the wrist joint?

Answer 10

synovial condyloid joint

Question 11

articulation of bones that forms the midcarpal joint?

Answer 11

proximal row of carpal bones articulate with distal row of carpal bones

Question 12

what type of joint is the midcarpal joint?

Answer 12

synovial plane joint

Question 13

articulation of bones that form the intercarpal joints?

Answer 13

articulations between individual carpal bones - e.g. scaphoid and lunate, lunate and triquetral

Question 14

what type of joint is the intercarpal joint?

Answer 14

synovial plane joint

Question 15

difference between the potential movements of intercarpal vs midcarpal joints?

Answer 15

both are synovial plane joints - midcarpal joint allows for more significant gliding movements

Question 16

what is the most common carpal injury?

Answer 16

scaphoid fracture

Question 17

what is the most common cause of a scaphoid fracture, and why is the scaphoid bone particularly vulnerable?

Answer 17

cause: falling on an outstretched hand

distal end of the radius articulates with the scaphoid bone - radius transfers all the weight to the scaphoid bone = fracture!

Question 18

why is there a risk of avascular necrosis in scaphoid fractures?

Answer 18

a fracture can disrupt distal-to-proximal blood flow to the proximal portion (which supplies scaphoid) = leads to avascular necrosis

Question 19

why might a scaphoid fracture be missed? what can happen if it goes untreated?

Answer 19

often missed on x-rays as they require an MRI for diagnosis

untreated - leads to complications like advanced osteoarthritis and impaired wrist mobility

Question 20

how many bones of the hand? - describe

Answer 20

5 metacarpals
12 phalanges - thumb has 2 (proximal and distal), other 4 fingers have 3 (proximal, middle, distal)

19 bones

Question 21

articulation of bones that form the carpometacarpal joint?

Answer 21

between carpal and metacarpal bones

Question 22

what type of joints are the carpometacarpal joints? which one is different & what movement does it allow for?

Answer 22

most CMC joints are synovial plane-type joints

only the thumb (the first CMC joint) is a synovial saddle joint - allows for flexion, extension, adduction, abduction, circumduction

Question 23

articulation of bones that form the metacarpophalangeal joints?

Answer 23

between distal ends of metacarpals & proximal phalanges

Question 24

what type of joint is the metacarpophalangeal joint? what movement does it allow for?

Answer 24

synovial condyloid joint

allows for flexion, extension, adduction, abduction, circumduction

Question 25

Which of the following pairs a joint with its correct type? A. Radiocarpal joint – Saddle B. Proximal radioulnar joint – Hinge C. Carpometacarpal joint of the thumb – Saddle D. Metacarpophalangeal joints – Pivot

Answer 25

C. Carpometacarpal joint of the thumb – Saddle

Question 26

What type of joint is the proximal radioulnar joint, and what movement does it allow? A. Hinge – Flexion/Extension B. Pivot – Pronation/Supination C. Plane – Sliding D. Ball and socket – Rotation

Answer 26

B. Pivot – Pronation/Supination

Question 27

Which of the following joints is incorrectly matched to its joint type? A. Intercarpal joints – Plane B. Distal radioulnar joint – Pivot C. Wrist joint (radiocarpal) – Ellipsoid D. Midcarpal joint – Saddle

Answer 27

D. Midcarpal joint – Saddle

Question 28

The radiocarpal joint permits which of the following movements? A. Pronation and supination B. Flexion/Extension and Abduction/Adduction C. Only circumduction D. Rotation only

Answer 28

B. Flexion/Extension and Abduction/Adduction

Question 29

Which of these statements about the distal radioulnar joint is TRUE? A. It allows abduction and adduction B. It is a hinge joint C. It is involved in wrist flexion D. It contributes to pronation and supination

Answer 29

D. It contributes to pronation and supination

Question 30

The metacarpophalangeal (MCP) joints are what type and allow which movements? A. Plane – Sliding B. Condyloid – Flexion/Extension, Abduction/Adduction C. Saddle – Rotation only D. Hinge – Flexion/Extension only

Answer 30

B. Condyloid – Flexion/Extension, Abduction/Adduction

Question 31

Which joint type is shared by both the intercarpal joints and the carpometacarpal joints (except thumb)? A. Condyloid B. Plane C. Saddle D. Hinge

Answer 31

B. Plane

Question 32

The interphalangeal joints are which type of synovial joint? A. Hinge B. Pivot C. Plane D. Ball and socket

Answer 32

A. Hinge

Question 33

Which joint is responsible for the opposition of the thumb? A. Metacarpophalangeal joint B. First carpometacarpal joint C. Scapholunate joint D. Proximal interphalangeal joint

Answer 33

B. First carpometacarpal joint

Question 34

what movements do the palmar and dorsal radiocarpal ligaments prevent?

Answer 34

palmar - prevents excessive wrist extension dorsal - prevents excessive wrist flexion

Question 35

ulnar collateral ligament - location? function?

Answer 35

location - from the ulnar styloid process to the triquetral & pisiform bones function - prevents excessive radial deviation of the hand

Question 36

what ligament runs from the radial styloid process to the scaphoid & lunate bones? what movement does it prevent?

Answer 36

radial collateral ligament - prevents excessive ulnar deviation of the hand

Question 37

palmar ligaments - location? structure? function?

Answer 37

location - at the anterior aspect of MCP, DIP & PIP joints structure - thickening of the joint capsules function - stabilises joints, prevents hyperextension

Question 38

deep transverse metacarpal ligaments - location? function?

Answer 38

location - extends between the heads of the 2nd to 5th metacarpals at the base of the knuckles function - resists separation of metacarpal bones from each other & gives hand stability

Question 39

collateral ligaments (of the hand) - location? function?

Answer 39

location - medial & lateral thickenings of joint capsules at MCP, DIP & PIP joints function - provide lateral stability to joints - makes separating fingers harder during flexion, easier during extension as the ligament is relatively relaxed

Question 40

what movements is the wrist capable of?

Answer 40

flexion/ extension ulnar deviation (adduction)/ radial deviation (abduction) circumduction

Question 41

what movements is the thumb capable of?

Answer 41

flexion (thumb across palm)/ extension adduction/ abduction opposition (tip of thumb & tip of finger) movements occur across a sagittal plane as thumb is at a right angle

Question 42

medial & lateral muscle borders of the anatomical snuff box?

Answer 42

medial - extensor pollicis longus lateral - extensor pollicis brevis & abductor pollicis brevis

Question 43

what bones form the floor of the anatomical snuff box?

Answer 43

scaphoid & triquetrium

Question 44

contents of the anatomical snuff box?

Answer 44

radial artery superficial branch of the radial nerve