Ucsf: Video E 48 Part 5 Msk Skeletal Trauma (Learning Radiology-Shoulder Dislocations)

Front 1

What are the anterior dislocation associated bony abnormalities

Back 1

hill-sachs
bankart

Front 2

What are the posterior should dislocation associated bony abnormalities

Back 2

trough sign
light bulb sign

Front 3

What is more common; anterior or inferior should dislocations

Back 3

anterior (96%)

Front 4

What percent of pts with anterior dislocation have a recurrence

Back 4

40%

Front 5

What is the mechanism of an anterior shoulder dislocation

Back 5

external rotaion and abduction

Front 6

What is a potential complication of an anterior shoulder dislocation

Back 6

axillary nerve damage

Front 7

Where does the humeral head go in a anterior dislocaton

Back 7

under the coracoid process (also known as subcoracoid dislocations)
On frontal plain film look for the glenoid and the humeral head will be medial and inferior to the glenoid

Front 8

What is the cause of a hills sachs deformity

Back 8

results from impaction of the posterior lateral surface of the humerus on the anterior rim of glenoid

Front 9

What percent of pts with anterior shoulder dislocations result in hill sachs defects

Back 9

50%

Front 10

What is a bankart fracture

Back 10

this is a fracture of the anterior glenoid rim

Front 11

What are 3 plain films images used to look at a shoulder dislocation

Back 11

frontal, axillary and Y-view

Front 12

What is a Y-view

Back 12

a lateral view of the scapula (you can tell bc the coracoid and the acromion and scapula body form a Y)

Front 13

Where is the humeral head located on a Y view of the shoulder

Back 13

centered inbetween the acromion and coracoid and slightly inferior

Front 14

Where is an anterior dislocation located on a Y-view of the scapula

Back 14

inferior to the coracoid

Front 15

What does an axillary view of the shoulder look like

Back 15

it is like a axillary CT cut through the shoulder

Front 16

What is anterior the acromion or coracoid?

Back 16

coracoid process

Front 17

What does an anterior dislocation look like on an axillary plain view of the shoulder

Back 17

it is anterior to the glenoid and superimposed on the coracoid

Front 18

What does a hills sachs deformity look like on a frontal of the shoulder

Back 18

it looks like someone took a bite out of the lateral aspect of the humeral head

Front 19

Do posterior dislocations of the shoulder ever go unrecognized

Back 19

yes, 50% of the time (frontal view is not sensitive)

Front 20

What views are typically required to diagnose a posterior dislocation

Back 20

y-view, axillary or trans-thoracic lateral

Front 21

What is the mechanism of a posterior shoulder dislocation

Back 21

axial load on an adducted and internally rotated arm

Front 22

What are common causes of a posterior shoulder dislocation
2

Back 22

convulsion disorder
electroshock therapy

Front 23

What are the imaging findings of a posterior dislocation

Back 23

under the acromion

Front 24

What is the light bulb sign

Back 24

this is the result of the humeral head being fixed in a internal rotation and the humeral head looks like a light bulb no matter what view

Front 25

What is the trough sign

Back 25

a fracture along the anteromedial aspect of the humeral head

Front 26

What is the causes of the trough sign

Back 26

the result of the humeral head hitting the posterior rim of the glenoid

Front 27

Can an inferior dislocation of the shoulder occur

Back 27

yes

Front 28

What is another name for inferior dislocation of the shoulder

Back 28

luxatio erecta

Front 29

What is the mechanism of an inferior dislocation of the shoulder

Back 29

hyperabduction

Front 30

What complications are associated with inferior shoulder dislocation

Back 30

rotator cuff tear
axillary nerve damage
fracture of acromion

Front 31

What percent of pts with an inferior shoulder dislocation have rotator cuff tears

Back 31

80%

Front 32

What happens to the humeral head in a inferior shoulder dislocation

Back 32

it rotates so the articular surface faces inferiorly

Front 33

What is a clinical sign of an inferior shoulder dislocation

Back 33

extremity is held over head and can be lowered

Front 34

Where is the humeral head in relation to the glenoid fossa in an inferior shoulder dislocation

Back 34

inferior to the glenoid