UL Radiology Revision Flashcards
What type of injury can be seen?
Surgical neck of humerus fracture
What nerve injury can be associated with a surgical neck fracture? How can this be tested?
Axillary nerve injury
Motor:
- Deltoid (abduction)
- Teres minor (lateral rotation)
Sensory:
- Upper lateral arm
What type of injury can be seen?
Surgical neck fracture
What happens during a anterior dislocation of the shoulder?
the humeral head comes to lie anterior, medial and somewhat inferior to its normal location and glenoid fossa
What injury can be seen?
Anterior shoulder dislocation
What nerve injury can be associated with an anterior shoulder dislocation?
Axillary nerve injury
What can cause posterior shoulder dislocations?
- Convulsive disorders
- Electrocution
- Trauma
What must you check for in posterior shoulder dislocations?
Bilateral dislocations
Why can posterior dislocations be missed initially on frontal radiographs in 50% of cases?
as the humeral head appears to be almost normally aligned with the glenoid
Which view is preferred for diagnosis of posterior shoulder dislocations?
Axillary view
What injury is this? What are the radiographic features?
Posterior shoulder dislocation
- Fixed internal rotation of the humeral head
- Widened glenohumeral joint
Who are supracondylar humeral fractures most commonly seen in?
Children (often 5-7)
What is the most common mechanism of injury for a supracondylar fracture?
FOOSH
What nerve and vessel injury can be associated with a supracondylar fracture? How can these be assessed?
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
Sometimes no obvious fracture line for a supracondylar fracture can be identified. What should you look for instead?
- 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
What injury can be seen?
Supracondylar fracture
What is the posterior fat pad sign?
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
What does a posterior fat pad sign indicate? What should you look for in adults? In children?
Indicates an elbow joint effusion that suggests a non-displaced fracture
In adults: radial head fracture
In children: supracondylar fracture
What is the anterior fat pad sign?
The elevation fof the anterior fat pad to create a silhouette
What does an anterior fat pad sign indicate? What should you look for in adults? Children?
Joint effusion as anterior fat pad is elevated away from humerus –> intra-articular fracture
In adults: radial head fracture
In children: supracondylar fracture
What is an occult fracture?
A hidden fracture (doesn’t appear on xray)
What is a joint effusion almost always indicative of?
Elbow fracture
Where does the anterior fat pad sit? Posterior?
Anterior - coronoid fossa
Posterior - olecranon fossa
Xray of patient with gout. Is this an elbow joint effusion? How can you tell?
- No - gout is affecting their olecranon bursa
- Normal orientation of anterior fat pad
- Posterior fat pad not seen
What can be seen here? What does this imply?
- Displacement of anterior fat pad –> joint effusion
- Posterior fat pad visible
What is the most common cause of an elbow joint effusion in adults?
Radial head or neck fracture
What is the most common cause of an elbow joint effusion in children?
Supracondylar fracture
What is a Colles fracture? How is it typically caused?
- Extra-articular fracture of the distal radius that occurs as a result of a FOOSH
- Can results in posterior displacement of radius
What features should be noted in a Colles fracture?
- Degree of radial fracture
- Presence of intra-articular fracture?
- Other fractures?
- Ulnar styloid?
- Carpal bones?
What type of injury is this? What should be noted?
Colles fracture
- Transverse fracture of radius
- Dorsal displacement and dorsal angulation, together with the radial tilt
- Ulnar styloid fracture
Associated nerve injury that can occur with a Colles fracture?
Median nerve injury –> delayed carpal tunnel syndrome
What is a greenstick fracture? Who are they normally seen in?
- Incomplete fractures of long bones (bone bends but doesn’t break)
- Affecting forearm and lower leg
- Affects young children (<10 normally)
What type of injury is this?
Greenstick fracture
What type of injury is this?
Greenstick fracture
How do AC dislocations typically occur?
Sports
- Direct blow or fall onto shoulder with an adducted arm
- FOOSH
Typical xray features of an AC dislocation?
- Widening of AC jiont
- Increased coracoclavicular distance
- Superior displacement of distal clavicle
What type of injury is this?
AC dislocation
Displaced vs nondisplaced
Extra vs intra-articular
