Flashcards in Shoulder/Elbow Anatomy Deck (52):
describe synovial membrane?
what happens if you tear synovial membrane?
describe articular cartilage
on surface of bones in a joint
Fibrous capsule reinforced by 3 things
what is the labrum for? 2 things
provides attachment site (e.g.. long head biceps)
what is intra-articular but extrasynovial in joints? purpose?
fat pad, used to distribute synovial fluid evenly during movement
What are discs and menisci for in joints? how are their blood and nerve supply?
weight bearing and shock absorption
blood and nerve supply to outer third
special feature of bursae?
may communicate with joint cavity/risk of infection spreading
characteristics of stable vs. mobile joints
congruent vs. incongruent articular surfaces
limited vs. increase ROM
tight vs. lax capsules/ligaments
4 main joints of the shoulder complex?
When do long bones ossify?
in utero at 8 weeks from transition from embryo to fetus
when do epiphyses appear?
generally after birth but if large baby could be before birth
What do the following humeral fractures endanger?
1. surgical neck
1. axillary nerve
2. radial nerve
3. median nerve and brachial artery
difference between anatomical and surgical neck?
anatomical is end of capsule
surgical is common site of fracture
What is the point of the acromioclavicular joint?
give the shoulder girdle a 'hinge' to allow for scapulo-humeral rhythm and allow scapula to move along posterior chest well.
likely site of clavicle fracture?
max change of curvature between lateral 1/3 and medial 2/3
Key features of sternoclavicular joint? 3 things
costoclavicular ligament to limit movement
what does a intra-articular disc in the sternoclavicular joint do?
increases complexity of movement
lateral disc: elevation depression
medial disc: rotation about longitudinal axis
structures endangered during a sternoclavicular subluxation?
subclavian artery and vein
What are the coracoclavicular ligaments?
ligaments from coracoid process to clavicle: main stabilizers of acromioclavicular joint
prevent upward displacement of clavicle
what does the acromioclavicular ligament do?
prevent upward displacement of clavicle
acromioclavicular joint is strong or weak capsule?
acromioclavicular subluxation grade 1,2,3?
1: stretched not torn
2. separation and AC ligaments torn
3. wide separation AC and coracoclavicular ligaments torn
5 layers of GH joint?
where does the capsule attach above and below the head of the humerus?
above: anatomical neck
below: surgical neck (makes pouch for increased ROM)
rotator cuff attachment blends into?
what happens if rotator cuff weak?
deltoid pull humerus upwards and lead to impingment of supraspinatus
what does the subacromial bursa do?
protects head of humerus from hitting acromion
subacromial bursa communicates?
shoulder dislocation most common one is?
how would a posterior shoulder dislocation happen?
how to test if axillary nerve damaged by dislocation?
C5 dermatomes sensory test however it's not perfect as peripheral nerves often overlap
2 types of synovial joints of the elbow are?
elbow complex has two joints, how many synovial cavities?
capitulum vs. trochlea is where?
What is in the fossae of distal humerus?
what is the coronoid process?
part of the proximal ulnar that articulates with humerus
what can be mistaken for a fracture on x-ray?
epiphyses -usually straight rather than jagged fracture
3 main ligaments of elbow
lateral/radial collateral lig
medial/ulnar collateral lig
what allows pronation and supination
the LCL attaches to annular ligament rather than a bone
what do the collateral ligaments resist in the elbow
abduction and adduction
max stability in elbow when?
what is the significance of carrying angle in elbow?
valgus could irritate ulnar nerve
where are the traction epiphyses in the distal humerus?
purpose of interosseus membrane?
attachment of muscles
What does the inferior RU joint have?
triangular fibrocartilage complex (disc)
in a 'ring' principle of bones what happens?
a fracture in one is associated with fracture in another
what does the distal RU joint disc do? what happens with age?
stabilizes the joint
more perforated with age
annular ligament in children is?
weaker more likely to dislocate with traction on extended arm
what is most common dislocation/fracture in elbow?
posterior dislocation with coronoid process fracture
whats the risk of a supracondylar fracture?
children more commonly damage brachial artery get Volkmann's ischemia and avascular necrosis of forearm muscles