Elbow Imaging Flashcards
Elbow fractures are common in
children
Account for 15% of all fractures and about 50% of UE fx in those under 18 yo
What is often mistaken as a fracture
secondary ossification centers
Long bones (humerus) primary ossification
8 wks gestation
At birth - what is ossified
Shaft of humerus, ulna, and radius
Articulating surfaces of these bones are still cartilaginous
Development of secondary ossification centers - fuse earlier in who
females
What is the acronym for secondary ossification centers
C - capitulum = 1 yr R - radius = 3 yr I - internal (med) epicondyle = 5 yr T - trochlea = 7 O - olecranon = 9 E - external (lat) epicondyle = 11
Ages of secondary ossification centers are ____ but
Debated
But order of appearance is agreed upon
What is the first to appear and when
Capitulum
1-2 years
Capitulum fuses with what and when
Fuses with the trochlea and lateral epicondyle during puberty
Secondary ossification center - radius
about 3 years old
Fusion - radius
15 years F
17 years M
Secondary ossification center - med epicondyle
4 years old
Fustion - med epicondyle
16 years female
18 years male
What is the last epiphysis to fuse
Medial epicondyle
Secondary ossification center - trochlea
about 7 years old
Fusion - trochlea
More irregularity than other elbow areas
First with capitulum and then with lateral epicondyle (during puberty) and then with humerus
Olecranon begins ossification when
9 years old
Olecranon closes when
15 years F
17 years M
Last ossification center to appear
Lateral epicondyle
When does the ossifcation center appear of the lateral epicondyle
10-12 years old
When does lat epicondyle fuse and what does it fuse to
During puberty
Fuses with capitulum and trochlea
14 years F, 17 years M
Routine projections of the elbow
AP
Lateral
Oblique (upon request) - Internal or External
AP Projection - provides a good view of what
Distal humerus and proximal radius/ulna
AP projection - position
Arm placed in ER
Elbow extension
Forearm supination
ANATOMIC POSITION
Proximal radius is comprised of
Radial head
Radial neck
Radial tuberosity
Capitulum and radius - extended position
No contact
Olecranon - when elbow is extended it is between
the epicondyles and in the fossa
Displacement of a fat pad is indicative of
inflammation in the area, most often secondary to a fracture
Carrying angle - define and describe
Ulna angled in a lateral direction in relationship to the humerus
5-15 degrees
Medial trochlea is more distal
A greater angulation of carrying angle seen on an AP radiograph can indicate what
possible fracture
Lateral projection - position
Elbow 90 flex
Forearm supination with thumb up
Lateral projection - what is placed next to the receptor
What direction does the ray go
Medial portion of the elbow
Central ray directed in a lateral to medial direction
Olecranon fracture - often due to
Traumatic force that impacts olecranon onto distal humerus
FOOSH - can cause transverse fx due to forced contraction of triceps
Olecranon fracture - what is more common - displaced or non
Displaced because of pull of triceps
The alignment of the radial head should be reviewed in relationship to
the capitulum
Teardrop area
Area where the epicondyles overlap
Disruption of teardrop area can indicate
supracondylar fx?
Oblique projection - when is it usually requested
pediatric trauma cases
Displaced ant fat pad AKA
sail sign
Internal oblique projection - position
Elbow extended
Forearm pronation
Central ray direction with internal oblique projection
Ant to Post
Internal oblique projection gives you a good view of what
Coronoid process
Also allows for close inspection of humeral ulnar articulation
External oblique projection - position
Elbow extension
Forearm supination
Central ray for external oblique projection
Anterior to Posterior
What is the most common oblique taken when fracture is suspected in children
External oblique projections
External oblique projection allows for examination of
Radial head Radial neck Radial tuberosity All without superiposition of the ulna All 3 elbow joints can be examined
Radius and ulna act as a ___ system
Ring system
Fx at any point may result in injury to another part of the ring
Standard projections for the forearm
Lateral and AP
Injury to forearm are said to occur in
proximal third, middle third, or distal third
What is visualized with AP forearm
Shafts of ulna and radius
Wrist and elbow joints too
What is visualized with lateral forearm
Shafts of ulna and radius
Wrist and elbow joints too
Proximal 1/3 - most common fracture
Monteggia fracture
Proximal ulnar fracture associated with radial head dislocations
Middle 1/3 - fractures in this area are common in
children
Middle 1/3 fracture that occurs in adults is usually due to ___
Often results in ___
high energy injuries
open fractures and neuro damage
A primary complication of middle 1/3 fracture
Compartment syndrome
Emergency care required - need a fasciotomy
Distal 1/3 - common type
Galeazzi fracture - seen in middle or distal 1/3 with accompanying dislocation of distal radioulnar joint and maybe also a fracture of the ulnar styloid
