Bones & Joints of the Upper Limb Flashcards Preview

Anatomy (Karen) > Bones & Joints of the Upper Limb > Flashcards

Flashcards in Bones & Joints of the Upper Limb Deck (78):
1

What are the features of a synovial joint?

  • articular cartilage (avascular & aneural)
  • fibrous capsule (collagen, elastin, fibroblasts)
    • may be reinforced by stabilizer muscles
    • strengthened by intrinsic ligaments
    • extrinsic/accessory ligaments may be primary stabilizers
  • synovial membrane lining non-articular surfaces

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2

What is haemarthrosis?

blood in a joint; caused by rupture of synovium which is highly vascularized

3

Effusion of a synovial joint refers to

overproduction of synovial fluid

4

Why do ligaments repair slowly?

Poor blood supply

5

What is the function of intracapsular fat pads?

spreading of synovial fluid with joint movement

fat pads are extrasynovial

6

What are discs/menisci?

  • act as schock absorbers and weight-bearers
  • have nerve & blood supply to the outer 3rd
  • typically found in knee (menisci)

7

What are bursae?

  • sacs containing synovial fluid
  • common wherever there is friction (eg patella, olecranon)
  • may or may not communicate with the joint cavity 
  • can become inflamed
    • eg olecranon bursitis

8

What are the joints of the shoulder complex?

  • sternoclavicular & acromioclavicular
  • glenohumeral
  • scapulothoracic (physiological/functional joint of scapula on posterior chest wall via fatty tissue)

9

Long bones commence ossification

in utero @ 8 weeks (embryo --> foetus)

epiphyses generally appear after birth but can appear in utero in longer bones

10

Fracture of the surgical neck of the humerus endangers

axillary nerve

common in elderly

11

Fracture of the mid-shaft of the humerus endangers

radial nerve

12

Fracture of the supracondylar region of the humerus endangers

median nerve, brachial artery

common in children

13

The anatomical neck of the humerus serves as

attachment site of the shoulder capsule

except medially where it drops down further (+ROM)

14

What lies between the tuberosities of the humerus?

bicipital/intertubercular groove lies between greater and lesser tuberosities of the humerus

 

this is hte groove for the long head of the biceps tendon

15

Where is the most common site of clavicular fracture?

Where the lateral concave 1/3rd changes to the medial convex 2/3rds

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16

Injury to the clavicle limits

ROM of upper limb; can't abduct arms above the head

acts as 'hinge' at acromioclavicular joint for scapula to slide on the posterior thoracic wall

17

On CXR, clavicular fractures present

depressed lateral 1/3rd pulled down by upper limb

elevated medial 2/3rds pulled up by sternomastoid

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18

The sternoclavicular joint is (type)

synovial

19

What is the function of the disc of the sternoclavicular joint?

divides the capsule:

lateral - elevation and depression

medial - rotation

20

What is the extrinsic ligament of the sternoclavicular joint?

costoclavicular ligament

forms a tight, strong joint capsule; stabilizes joint

attaches clavicle to underside of 1st rib

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21

What structures are endangered by sternoclavicular dislocation/subluxation?

rare; more likely fractured via blunt trauma

subclavian vein & artery

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22

What type of joint is the acromioclavicular joint?

plane (sagittal) synovial

23

Dislocation or subluxation of the acromioclavicular joint usually occurs

anterioposteriorly

24

The main stabilizer of the acromioclavicular joint is

coracoclavicular ligament

prevents upward rotation of the clavicle at the AC joint

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25

What structures attach to the glenoid labrum?

long head of biceps tendon (superior)

glenohumeral ligaments

26

What structures penetrate the capsule of the shoulder joint?

subscapular bursa

long head of biceps

27

What muscles stabilize the glenohumeral capsule?

Rotator cuff:

Supraspinatus (top)

Infraspinatus (back)

Teres minor (back)

Subscapularis (front)

28

Infraspinatus and teres minor (function)

externally rotate shoulder

29

Supraspinatus (function)

abduction of shoulder (w/deltoid)

30

Subscapularis (function)

internal rotation of shoulder

31

How does supraspinatus impingement occur?

weak RC muscles cannot oppose strength of deltoid

supraspinatus tendon gets pinched between head of humerus and the superior labrum

32

How does subacromial bursitis occur?

inflammation of bursa w/overproduction of synovial fluid

w/weak RC bursa can be impinged between head of humerus and acromion process/coracoacromial ligament) in abduction

difficult to differentiate from supraspinatus tears or calcification

33

The most common type of shoulder dislocation is

anterior & inferior; force applied to abducted and externally rotated arm

(posterior is less common; grand mal epileptic attack, electric shock - sudden force transmitted through upper limb)

34

What structures are endangered by shoulder dislocation?

axillary nerve

supplies deltoid, teres minor & overlying skin (dermatome C5 insertion of deltoid, military badge area)

35

What are the types of synovial joints?

  • ball & socket
  • hinge
  • plane
  • pivot
  • condylar
  • saddle

36

The collateral ligaments of the elbow attach to

medial & lateral epicondyles

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37

Collateral ligaments of the elbow resist

abduction and adduction (relative to the arm)

38

The medial/ulnar collateral ligament runs

from medial epicondyle to the coronoid & olecranon processes of the ulna

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39

The lateral/radial collateral ligament runs from

lateral epicondyle to the annular ligament

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40

The annular ligament

encloses the head of the radius on the proximal radioulnar joint

attachment of LCL

permits pronation and supination of the forearm

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41

The elbow joint is most secure in

extension (ligaments taut)

42

What is valgus angulation?

in extension, the forearm points laterally by 165 degrees

43

What is cubitus valgus?

increased valgus angulation of the elbow (increased lateral displacement of forearm) that stretches the MCL and ulnar nerve

44

Movements of the radioulnar joints

rotational: pronation & supination

45

Radioulnar joints (structure)

synovial pivot joints

(inferior includes disc)

46

What is the function of the IOM?

  • joins radioulnar joints to produce pronation & supination
  • transmits forces
    • wrist - from radius to ulna (elbow) up arm
    • fracture of one bone can cause fracture in the other (ring principle)
  • attachment for deep muscles of the forearm

47

Dislocation of the elbow is most commonly

posterior

can result in fracture of the coronoid process & Volkmann's ischaemia (vascular necrosis of forearm due to spasm/stretch of brachial artery or its branches)

48

What is tennis elbow?

lateral epicondylitis of extensor carpi radialis brevis tendon (extension, pronation, and wrist flexion)

49

Epicondyles are susceptible to

traction injuries because they are traction epiphyses

(muscles/tendons can pull off the epiphyses)

50

Fracture of the medial epicondyle endangers

ulnar nerve

51

Which carpal bones articulate with the radius at the wrist?

scaphoid & lunate (1 & 2)

triquetral (3) in ulnar deviation

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52

What are the names of the proximal carpal bones?

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  1. scaphoid
  2. lunate
  3. triquetral
  4. pisiform (sesamoid in tendon of flexor carpi ulnaris)

53

What are the names of the distal carpal bones?

Q image thumb

  1. trapezium
  2. trapezoid
  3. capitate
  4. hamate

54

What bones form the anatomical snuffbox?

proximal boundary: styloid process of radius

floor: scaphoid bone

55

What are the bony attachments of the flexor retinaculum?

lateral/radial: scaphoid tubercle and trapezium tubercle

medial/ulnar: pisiform, hook of hamate

56

What movements occur at the radiocarpal joint?

  • flexion/extension
  • abduction (radial deviation)/adduction (ulnar deviation)
  • rotational movements are inhibited by the right-angle orientation of the articular surfaces for scaphoid and lunate on the distal radius
  • these movements also occur at the midcarpal joint (between proximal and distal carpal bones)

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57

Which movements are greater at the radiocarpal joint?

flexion > extension

ulnar deviation > radial deviation

58

What type of joint is the radiocarpal joint?

synovial ellipsoid

59

Which is the largest bone of the hand?

capitate

60

What is the clinical significance of the capitate bone?

largest tf receives and transmits forces in a fall

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61

Which movements are greater at the midcarpal joints?

extension > flexion

radial deviation > ulnar

cannot actually be distinguished

62

What is the function of the palmar radiocarpal ligaments?

anchored to the radius, prevent carpal bones from sliding medially to space between proximal carpals and ulna

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63

What is the function of the radio-scapho-lunate ligament?

  • goes from radius over scaphoid, attaches to scaphoid and encircles lunate
  • provides an archway over scaphoid and lunate that anchors them
  • damage to this ligament results in dislocation of the lunate bone

64

Which carpal bone is most commonly dislocated?

lunate; may involve damage to radio-scapho-lunate ligament

65

Vessels are transmitted to carpal bones via

ligaments because there are no tendons to carpal bones

66

What is a Colles fracture and how does it present?

  • fracture of the distal radius
    • most common fracture of upper limb (w/clavicle)
      • especially in elderly, osteoporosis
  • 'dinner fork' on X-ray
    • distal portion remains articular w/scaphoid
    • proximal to fracture the radius pops upwards

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67

What is the most commonly fractured carpal bone?

scaphoid; along waist (where vascula foramina lie)

68

What is endangered in scaphoid fractures?

  • radial artery branches passing through the vascular foramina
  • can result in avascular necrosis of the proximal pole of the scaphoid if undetected
  • tf several X-rays taken over a period of days in case scaphoid fracture is obscured by swelling (will be present in anatomical snuffbox)

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69

What are the movements of the metacarpophalangeal joints?

flexion/extension

abduction/adduction

70

What are the movements of the interphalangeal joints?

flexion/extension only

71

What type of joint are the carpometacarpal joints?

synovial

72

What is unique about the articular surface of the trapezium?

two concave survaces in opposite directions; forms the saddle joint of the thumb and allows opposition

73

What is the function of the deep transverse metacarpal ligament?

links & stabilizes carpometacarpal joints II-V

(ROM increases radial to ulnar)

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74

What type of joint are the metacarpalphalangeal joints?

condyloid synovial joints

75

What is the function of the dorsal and volar/palmar plates?

fibrocartilage that expands the articular surface on the proximal end/base of the phalanges with the distal metacarpal condyles, & at the interphalangeal joints

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76

Collateral ligaments of the MCP joints tighten in

flexion; harder to abduct in flexion than extension

77

What is a 'swan neck' deformity of the finger?

  • force applied to volar aspect of the MCP or IP joint results in hyperextension of the joint an compensatory flexion of the terminal joint
  • distal metacarpal can break through the volar plate

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78

What is a Boutonniere deformity of the finger?

  • force to the dorsal aspect of the MCP or IP joint causes flexion of the joint and compensatory hyperextension of the distal joint
  • bone can break through the dorsal plate into the capsule or extensor tendons

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