Peds Radiology Newsletter, Elbow Fractures

Pediatric Elbow Fractures
When looking at radiographs of the elbow after trauma a methodical review of the radiographs is needed .
You should ask yourself the following important questions.
Is there a sign of joint effusion?
After trauma this almost always indicates the presence of hemarthrosis due to a fracture (either visible or
Is there a normal alignment between the bones?
In children dislocations are frequent and can be very subtle.
Are the ossification centers normal?
Is the piece of bone that you're looking at a normal ossification center and is this ossification center in the
normal position.
Look especially for the position of the radial epiphysis and the medial epicondyle.
Is there a subtle fracture?
Some of the fractures in children are very subtle.
So you need to be familiar with the typical picture of these fractures.
Fat Pad Sign and Joint Effusion
Normally on a lateral view of the elbow
flexed in 90degrees. A fat pad is seen
on the anterior aspect of the joint .
This is normal fat located in the joint
Normal Anterior Fat Pad
On the posterior side no fat pad is
seen since the posterior fat is located
within the deep intercondylar fossa.
Positive Fat Pad Sign
Distention of the joint will cause the
anterior fat pad to become elevated
and the posterior fat pad to become
An elevated anterior lucency or a
visible posterior lucency on a true
lateral radiograph of an elbow flexed at
90 degrees is described as a positive
fat pad sign.
Posterior Fat Pad
There are two important lines which help
in the diagnosis of dislocation and fracture
These are the Radiocapitellar line and the
Anterior humeral line.
Radiocapitellar Line
A line drawn through the center of the
radial neck should pass through the center
of the capitellum, whatever the positioning
of the patient, since the radius articulates
with the capitellum.
In dislocation of the radius this line will not
pass through the center of the capitellum.
On the left we see, that the radiocapitellar
line goes through center of the capitellum
on every radiogragh even though C and D
are not well positioned.
Notice supracondylar fracture in B.
On the left more examples of the
radiocapitellar line.
The right lower image shows an obvious
dislocation of the radius.
Anterior Humeral Line
A line drawn on a lateral view along the
anterior surface of the humerus should
pass through the middle third of the
This line is called the Anterior Humeral
In cases of a supracondylar fracture the
anterior humeral line usually passes
through the anterior third of the capitellum
or in front of the capitellum due to
posterior bending of the distal humeral
On the left the anterior humeral line
passes through the anterior third of the
This indicates that the condyles are
displaced dorsally (i.e. supracondylar
Ossification Centers
There are 6 ossification centers around
the elbow joint.
They appear and fuse to the adjacent
bones at different ages.
It is important to know the sequence of
appearance since the ossification centers
always appear in a strict order.
This order of appearance is specified in
the mnemonic C-R-I-T-O-E (Capitellum Radius - Internal or medial epicondyle Trochlea - Olecranon - External or lateral
The ages at which these ossification
centers appear are highly variable and
differ between individuals.
It is not important to know these ages, but
as a general guide you could remember 13-5-7-9-11 years.
The Trochlea has two or more ossification
centres which can give the trochlea a
fragmented appearance.
On a lateral view the trochlea ossifications
may project into the joint.
They should not be mistaken for loose
intra-articular bodies (arrow).
Common Pediatric Elbow Fractures
Supracondylar Fractures
These fractures account for more than
60% of all elbow fractures in children.
More than 95% of supracondylar fractures
are hyperextension type due to a fall on
the outstretched hand:
The elbow becomes locked in
The olecranon is pushed into the
olecranon fossa causing the anterior
humeral cortex to bend and eventually
Supracondylar Fractures
If there is only minimal or no displacement
these fractures can be occult on
The only sign will be a positive fat pad
Usually there is some displacement and
the anterior humeral line will not pass
through the center of the capitellum but
through the anterior third or even anterior
to the capitellum (figure).
If the force continues both the anterior and
posterior cortex will fracture.
Gartland Type I fractures are often
difficult to see on X-rays since there is
only minimal displacement.
Most of these fractures consist of
greenstick or torus fractures.
The only clue to the diagnosis may be a
positive fat pad sign.
These patients are treated with casting.
Type III
In Gartland type II fractures there is
displacement but the posterior cortex is
There may be some rotation. These
fractures require closed reduction and
some need percutaneous fixation if a longarm cast does not adequately hold the
Gartland type III fractures are
completely dislocated and are at risk for
malunion and neurovascular
They require reduction by closed or if
necessary open means. Stabilization is
maintained with either two lateral pins or
medial lateral cross pin technique.
Malunion will result in the classic 'gunstock' deformity due to rotation or inadequate correction.
Posterolateral displacement of the distal fragment can be associated with injury to the neurovascular bundle which is
displaced over the medial metaphyseal spike.
Nerve injury almost always results in neuropraxis that resolves in 3-4 months.
Vascular injury usually results in a pulseless but pink hand.
Conservative management and vascular intervention have the same outcome.
A pulseless and white hand after reduction needs exploration.
Lateral Condyle Fractures
This fracture is the second most common
distal humerus fracture in children. They
occur between the ages of 4 and 10
years. These fractures occur when a
varus force is applied to the extended
elbow. They tend to be unstable and
become displaced because of the pull of
the forearm extensors.
Treatment strategies are therefore based
on the amount of displacement.
Undisplaced fractures are treated with a
long arm cast. These fractures must be
carefully monitored as they have a
tendency to displace. At follow up both AP
and Oblique views are taken after removal
of the cast.
Since these fractures are intra-articular
they are prone to nonunion because the
fracture is bathed in synovial fluid.
Lateral condyle fractures are classified
according to Milch. They are Salter-Harris
IV epiphysiolysis fractures.
Most are Milch II fractures that travel from
the lateral humeral metaphysis above the
epiphysis and exit through the lateral
crista of the trochlea leading to an
unstable humeral ulnar articulation.
Once displaced fractures consolidate in a
malunited position, treatment is difficult
and fraught with complications. For this
reason surgical reductions are
recommended within the first 48 hours.
Open reduction is indicated for all
displaced fractures and those
demonstrating joint instability.
The diagnosis of a lateral condyle fracture can be challenging.
Fracture lines are sometimes barely visible .
Remembering the fact that the lateral condyle fracture is the
second most common elbow-fracture in children and because
you know where to look for will help you.
Lateral Condyle Fracture Examples
Proximal Fractures of the Radius
In adults fractures usually involve the
articular surface of the radial head.
In children however it's the radial neck that
fractures because the metaphyseal bone
is weak due to constant remodelling.
Usually it is a Salter Harris II fracture.
If there is no displacement it can be
difficult to make the diagnosis.
Olecranon Fractures
Olecranon fractures in children are less
common than in adults. They are
associated with radial neck fractures and
radial dislocations.
Monteggia’s Fracture
Ulna fracture with radial head dislocation.
Closed reduction.
4 Types:
Galleazzi’s Fracture
Radius fracture with radioulnar joint
Fall onto extended arm.
Anterior interosseous nerve.
Treated with open reduction.
I - Extension type (60%) - ulna
shaft angulates anteriorly
(extends) and radial head
dislocates anteriorly.
II - Flexion type (15%) - ulna
shaft angulates posteriorly
(flexes) and radial head
dislocates posteriorly.
III - Lateral type (20%) - ulna
shaft angulates laterally (bent to
outside) and radial head
dislocates to the side.
IV - Combined type (5%) - ulna
shaft and radial shaft are both
fractured and radial head is
dislocated, typically anteriorly