UL Radiology Revision

Question 1

What type of injury can be seen?

Answer 1

Surgical neck of humerus fracture

Question 2

What nerve injury can be associated with a surgical neck fracture? How can this be tested?

Answer 2

Axillary nerve injury

Motor:

• Deltoid (abduction)
• Teres minor (lateral rotation)

Sensory:

• Upper lateral arm

Question 3

What type of injury can be seen?

Answer 3

Surgical neck fracture

Question 4

What happens during a anterior dislocation of the shoulder?

Answer 4

the humeral head comes to lie anterior, medial and somewhat inferior to its normal location and glenoid fossa

Question 5

What injury can be seen?

Answer 5

Anterior shoulder dislocation

Question 6

What nerve injury can be associated with an anterior shoulder dislocation?

Answer 6

Axillary nerve injury

Question 7

What can cause posterior shoulder dislocations?

Answer 7

• Convulsive disorders
• Electrocution
• Trauma

Question 8

What must you check for in posterior shoulder dislocations?

Answer 8

Bilateral dislocations

Question 9

Why can posterior dislocations be missed initially on frontal radiographs in 50% of cases?

Answer 9

as the humeral head appears to be almost normally aligned with the glenoid

Question 10

Which view is preferred for diagnosis of posterior shoulder dislocations?

Answer 10

Axillary view

Question 11

What injury is this? What are the radiographic features?

Answer 11

Posterior shoulder dislocation

• Fixed internal rotation of the humeral head
• Widened glenohumeral joint

Question 12

Who are supracondylar humeral fractures most commonly seen in?

Answer 12

Children (often 5-7)

Question 13

What is the most common mechanism of injury for a supracondylar fracture?

Answer 13

FOOSH

Question 14

What nerve and vessel injury can be associated with a supracondylar fracture? How can these be assessed?

Answer 14

Median nerve (anterior interosseous

• Motor: flexion of fingers (make a fist)
• Sensory: lateral 3 1/2 fingers and palm

Brachial artery

• Cool temp
• Pallor
• Delayed capillary refill time

Question 15

Sometimes no obvious fracture line for a supracondylar fracture can be identified. What should you look for instead?

Answer 15

• Anterior fat pad
  
  • Elevated due to joint effusion
• Posterior fat pad
• Anterior humeral line should intersect the middle third of the capitellum in most children

Question 16

What injury can be seen?

Answer 16

Supracondylar fracture

Question 17

What is the posterior fat pad sign?

Answer 17

a lucent crescent of fat located in the olecranon fossa on a true lateral view of an elbow joint with the elbow flexed at a right angle

Question 18

What does a posterior fat pad sign indicate? What should you look for in adults? In children?

Answer 18

Indicates an elbow joint effusion that suggests a non-displaced fracture

In adults: radial head fracture

In children: supracondylar fracture

Question 19

What is the anterior fat pad sign?

Answer 19

The elevation fof the anterior fat pad to create a silhouette

Question 20

What does an anterior fat pad sign indicate? What should you look for in adults? Children?

Answer 20

Joint effusion as anterior fat pad is elevated away from humerus –> intra-articular fracture

In adults: radial head fracture

In children: supracondylar fracture

Question 21

What is an occult fracture?

Answer 21

A hidden fracture (doesn’t appear on xray)

Question 22

What is a joint effusion almost always indicative of?

Answer 22

Elbow fracture

Question 23

Where does the anterior fat pad sit? Posterior?

Answer 23

Anterior - coronoid fossa

Posterior - olecranon fossa

Question 24

Xray of patient with gout. Is this an elbow joint effusion? How can you tell?

Answer 24

• No - gout is affecting their olecranon bursa
• Normal orientation of anterior fat pad
• Posterior fat pad not seen

Question 25

What can be seen here? What does this imply?

Answer 25

* Displacement of anterior fat pad --\> **joint effusion** * Posterior fat pad visible

Question 26

What is the most common cause of an elbow joint effusion in adults?

Answer 26

Radial head or neck fracture

Question 27

What is the most common cause of an elbow joint effusion in children?

Answer 27

Supracondylar fracture

Question 28

What is a Colles fracture? How is it typically caused?

Answer 28

* Extra-articular fracture of the **distal radius** that occurs as a result of a FOOSH * Can results in posterior displacement of radius

Question 29

What features should be noted in a Colles fracture?

Answer 29

* Degree of radial fracture * Presence of intra-articular fracture? * Other fractures? * Ulnar styloid? * Carpal bones?

Question 30

What type of injury is this? What should be noted?

Answer 30

Colles fracture * Transverse fracture of radius * Dorsal displacement and dorsal angulation, together with the radial tilt * Ulnar styloid fracture

Question 31

Associated nerve injury that can occur with a Colles fracture?

Answer 31

Median nerve injury --\> delayed carpal tunnel syndrome

Question 32

What is a greenstick fracture? Who are they normally seen in?

Answer 32

* Incomplete fractures of long bones (bone bends but doesn't break) * Affecting forearm and lower leg * Affects young children (\<10 normally)

Question 33

What type of injury is this?

Answer 33

Greenstick fracture

Question 34

What type of injury is this?

Answer 34

Greenstick fracture

Question 35

How do AC dislocations typically occur?

Answer 35

Sports * Direct blow or fall onto shoulder with an adducted arm * FOOSH

Question 36

Typical xray features of an AC dislocation?

Answer 36

* Widening of AC jiont * Increased coracoclavicular distance * Superior displacement of distal clavicle

Question 37

What type of injury is this?

Answer 37

AC dislocation

Question 38

Displaced vs nondisplaced Extra vs intra-articular

Answer 38