Shoulder/Elbow Anatomy

Question 1

describe synovial membrane?

Answer 1

highly vascular/neuro

Question 2

what happens if you tear synovial membrane?

Answer 2

haemarthrosis

Question 3

describe articular cartilage

Answer 3

on surface of bones in a joint
avascular
aneural

Question 4

Fibrous capsule reinforced by 3 things

Answer 4

stabilizer muscles
intrinsic ligaments
extrinsic/accessory ligaments

Question 5

what is the labrum for? 2 things

Answer 5

deepens glenoid

provides attachment site (e.g.. long head biceps)

Question 6

what is intra-articular but extrasynovial in joints? purpose?

Answer 6

fat pad, used to distribute synovial fluid evenly during movement

Question 7

What are discs and menisci for in joints? how are their blood and nerve supply?

Answer 7

weight bearing and shock absorption

blood and nerve supply to outer third

Question 8

special feature of bursae?

Answer 8

may communicate with joint cavity/risk of infection spreading

Question 9

characteristics of stable vs. mobile joints

Answer 9

congruent vs. incongruent articular surfaces
limited vs. increase ROM
tight vs. lax capsules/ligaments

Question 10

4 main joints of the shoulder complex?

Answer 10

sternoclavicular
acromioclavicular
scapulothoracic
gleno-humeral

Question 11

When do long bones ossify?

Answer 11

in utero at 8 weeks from transition from embryo to fetus

Question 12

when do epiphyses appear?

Answer 12

generally after birth but if large baby could be before birth

Question 13

What do the following humeral fractures endanger?

1. surgical neck
2. midshaft
3. supracondylar

Answer 13

1. axillary nerve
2. radial nerve
3. median nerve and brachial artery

Question 14

difference between anatomical and surgical neck?

Answer 14

anatomical is end of capsule

surgical is common site of fracture

Question 15

What is the point of the acromioclavicular joint?

Answer 15

give the shoulder girdle a ‘hinge’ to allow for scapulo-humeral rhythm and allow scapula to move along posterior chest well.

Question 16

likely site of clavicle fracture?

Answer 16

max change of curvature between lateral 1/3 and medial 2/3

Question 17

Key features of sternoclavicular joint? 3 things

Answer 17

intra-articular disc
strong capsule
costoclavicular ligament to limit movement

Question 18

what does a intra-articular disc in the sternoclavicular joint do?

Answer 18

increases complexity of movement
lateral disc: elevation depression
medial disc: rotation about longitudinal axis

Question 19

structures endangered during a sternoclavicular subluxation?

Answer 19

subclavian artery and vein

Question 20

What are the coracoclavicular ligaments?

Answer 20

ligaments from coracoid process to clavicle: main stabilizers of acromioclavicular joint
prevent upward displacement of clavicle

Question 21

what does the acromioclavicular ligament do?

Answer 21

prevent upward displacement of clavicle

Question 22

acromioclavicular joint is strong or weak capsule?

Answer 22

weak

Question 23

acromioclavicular subluxation grade 1,2,3?

Answer 23

1: stretched not torn
2. separation and AC ligaments torn
3. wide separation AC and coracoclavicular ligaments torn

Question 24

5 layers of GH joint?

Answer 24

bones
labrum
capsule
tendons/rotator cuff
coraco-acromial ligaments/bursae

Question 25

where does the capsule attach above and below the head of the humerus?

Answer 25

above: anatomical neck below: surgical neck (makes pouch for increased ROM)

Question 26

rotator cuff attachment blends into?

Answer 26

capsule

Question 27

what happens if rotator cuff weak?

Answer 27

deltoid pull humerus upwards and lead to impingment of supraspinatus

Question 28

what does the subacromial bursa do?

Answer 28

protects head of humerus from hitting acromion

Question 29

subacromial bursa communicates?

Answer 29

Nope.

Question 30

shoulder dislocation most common one is?

Answer 30

anterior-inferiorly

Question 31

how would a posterior shoulder dislocation happen?

Answer 31

electric shock | epileptic fit

Question 32

how to test if axillary nerve damaged by dislocation?

Answer 32

C5 dermatomes sensory test however it's not perfect as peripheral nerves often overlap

Question 33

2 types of synovial joints of the elbow are?

Answer 33

hinge | pivot

Question 34

elbow complex has two joints, how many synovial cavities?

Answer 34

one

Question 35

capitulum vs. trochlea is where?

Answer 35

capitulum: lateral trochlea: medial

Question 36

What is in the fossae of distal humerus?

Answer 36

fat pads

Question 37

what is the coronoid process?

Answer 37

part of the proximal ulnar that articulates with humerus

Question 38

what can be mistaken for a fracture on x-ray?

Answer 38

epiphyses -usually straight rather than jagged fracture

Question 39

3 main ligaments of elbow

Answer 39

lateral/radial collateral lig medial/ulnar collateral lig annular lig

Question 40

what allows pronation and supination

Answer 40

the LCL attaches to annular ligament rather than a bone

Question 41

what do the collateral ligaments resist in the elbow

Answer 41

abduction and adduction

Question 42

max stability in elbow when?

Answer 42

full extension

Question 43

what is the significance of carrying angle in elbow?

Answer 43

valgus could irritate ulnar nerve

Question 44

where are the traction epiphyses in the distal humerus?

Answer 44

epicondyles

Question 45

purpose of interosseus membrane?

Answer 45

allow pron/sup transmit forces attachment of muscles

Question 46

What does the inferior RU joint have?

Answer 46

triangular fibrocartilage complex (disc)

Question 47

in a 'ring' principle of bones what happens?

Answer 47

a fracture in one is associated with fracture in another

Question 48

what does the distal RU joint disc do? what happens with age?

Answer 48

stabilizes the joint | more perforated with age

Question 49

annular ligament in children is?

Answer 49

weaker more likely to dislocate with traction on extended arm

Question 50

what is most common dislocation/fracture in elbow?

Answer 50

posterior dislocation with coronoid process fracture

Question 51

whats the risk of a supracondylar fracture?

Answer 51

children more commonly damage brachial artery get Volkmann's ischemia and avascular necrosis of forearm muscles

Question 52

what is suceptible to injury in medial epicondyle fracture?

Answer 52

ulnar nerve