How to solve the

maze of diagnosis of

the elbow fractures in

children

Dr Taral V Nagda

Pediatric Orthopedic Surgeon Hinduja Hospital Saifee Hospital Jupiter Hospital Mumbai Director Institute of Pediatric Orthopedic Disorders www.ipodindia.org Helpline 09320141234 09320151234

The pediatric elbow is a maze with four articulations and six ossification centres.

There are more han a dozen different types of injuries possible and many can be

difficult to differentiate from one other. Discussed here are 12 easy to follow

guidelines to diagnose accurately an elbow injury in children radiologically. These

guidelines are as follows:

1. Take a proper AP and lateral view

2. Draw the radio capitellar line and know ulno humeral relationship

3. Draw the anterior humeral line

4. Draw Bowmann line

5. Look at the fat pads

6. Know the ossification centres

7. Take xray of the opposite elbow

8. Take a traction view

9. Take a stress view

10. Take internal oblique view

11. Visualise the unossified cartilage with MRI or USG

12. Do an arthrogram

Let us go through the steps one by one…

1 Take a proper AP and Lateral view

Taking a proper AP view in an injured elbow is a challenge. In an injured elbow It

may not be possible to extend the arm. The reduction of supracondylar fracture is

done with elbow flexed making it necessary to take a Jone’s view

In a flexed elbow the radiology technicians many times take AP view with beam

directed at the angle of elbow which makes interpretation difficult due to overlap

between humerus and forearm bones. As one can neither see clearly lower end of

humerus or upper end of forearm bones this is referred to as the loser’s view. It may

be better to take separate AP of lower humerus and upper forearm.

For taking lateral xray the forearm must be supinated and upper arm must be

horizontal to the table as shown in the figure below

A true ulnoradial lateral view thus obtained is important to detect the rotational

malalignment in supracondylar fractures

Correct rotation Malrotation

2 Draw the radio capitellar line and know ulno humeral

relationship:

What is normal

A line drawn through shaft of radius always goes through centre of lateral

condyle ossification. This is in all views of elbow and all positions of elbow. As

the lateral condyle is the first ossification centre in elbow to appear the sign is

reliable even in young kids.

What happens in injured elbow

Conditions where the radial line passes through centre of capitellum

a. Normal elbow

b. Supracondylar fracture

c. Complete physeal separation

d. Undisplased lateral condyle fractures

Conditions where the radial line does not pass through centre of capitellum

a. Elbow dislocation

b. Displased lateral condyle fractures

c. Monteggia fracture dislocation

d. Radial head dislocation

SC # in position Displased

supracondylar fracture

and complete physeal

separation

Displaced Lateral condyle

fracture

Elbow Dislocation

Conditions where humero ulnar relationship is maintained

a. Normal elbow

b. All lateral condyle fractures

c. Monteggia fracture dislocation

d. Isolated radial head dislocation

Conditions where humero ulnar relationship is disrupted

a. Supracondylar fracture

b. Complete physeal separation

c. Elbow dislocation

Condition RC relationship Ulno humeral relationship

1 Normal elbow N N

2 Supracondylar fracture N D

3 Complete Physeal disruption

N D

4 Undisplased lateral condyle fractures

N N

5 Displaced Lateral condyle fractures

D N

6 Elbow dislocation D D

7 Monteggia fracture dislocation

D N

3.Draw the anterior humeral line

What is normal

Normally the anterior humeral line passes through middle of capitellum

What happens in in jured elbow

In extension type supracondylar fracture it passes anterior to center of capitellum

In flexion type supracondylar fractures it passes posterior to the capitellum

Normal Extension type

supracondylar

fracture

Flexion type

supracondylar

fracture

4.Measure the Bowmann angle

In the flexed elbow it is difficult to

determine the carrying angle of

elbow The Baumann an gle

which is the angle between line

through lateral condyle physis

and a perpendicular to humerus

axis represents the carrying

angle

What is normal

Baumann angle of 65-80 is normal

with a mean of 75

What happens in injured elbow

Baumann angle more than 80 suggests cubitus varus and less than 65

represents cubitus valgus This is useful in assessing quality of reduction in

supracondylar fractures

Bowmann

angle

Bowmann angle

75 Normal

alignment

Bowmann Angle

85 Cubitus

Varus

Bowmann angle

75 Normal

alignment

5. Look at the fat pad

The fat pad sign is a sign that is sometimes seen on lateral radiographs of the

elbow following trauma. Elevation of the anterior and posterior fat pads of the elbow

joint suggests the presence of an occult fracture. A small anterior fat pad may be

present in normal pediatric elbows.

The fat pad sign is invaluable in assessing for the presence of an intra-articular

fracture of the elbow. A anterior fat pad is often normal. However a posterior fat pad

seen on a lateral x-ray of the elbow is always abnormal

6. Know the ossification centres

The numerous ossification centers, which appear at different tines and fuse with

each other at different times, are confusing in a diagnostic setting because they can

often be mistakenly interpreted as fractures

In contrast a fracture may appear like an epiphyseal centre. What appears like a

medial epicondyle fracture at 5 year age may actually be a medial condylar fracture

with metaphyseal fragment giving appearance of the medial epicondyle

This fracture in a 6 year old is

a medial condyle fracture

The bony fracgment

represents a small

metaphyseal part of large

cartilaginous fracture

fracgment

7. Take xray of the opposite side

The timing of appearances of the epiphyseal ossification centres can vary

Whenever in doubt it is always better to take xray of the opposite side to

compare. This is specially helpful in fractures of medial condyle v/s

epicondyle, fractures of olecranon apophyses and intraarticular fractures

Injured elbow Injured elbow Normal elbow comparison

view helps to know the degree

of displacement

8. Take a traction view

In rotated and overlapped lateral condyle and supracondylar fractures it

becomes very difficult to diagnose the level of fractures due to overlap of the

fragments In these cases a traction view can greatly help. This view also

helps when the fracture line is oblique

The rotated fragment gives

impression of lateral condyle

fracture

The traction view shows that it is

a supracondylar fracture

9 Take stress views

Stress views are important to differenciate between type 1 and 2 lateral

condyle fractures. They also help to know the degree of ligamentous injury in

an epicondyle fracture

The stress views suggest

unstable lateral condyle

fracture which needs fixation

10 Take oblique xrays

Internal oblique view accurately shows the profile and displacement of a lateral

condyle fracture. Similarly internal and external oblique column views are important

to assess reduction in supracondylar fractures

On AP view one gets impression of an undisplaced

fracture but Internal oblique view shows the correct

degree of displacement of lateral condyle fractre

11 Visualize the unossified bone and articular surface by

MRI or ultrasound

In medial condyle fractures , some lateral condyle fractures, complete physeal

separation in neonate and complex elbow trauma it may become necessary to see

the radiologically unseen anatomy by doing an MRI or ultrasound. It also may be

indicated when differentiating between traumatic and post infective physeal

separations

MRI in this minimally displaced lateral condyle fracture

shows extension of the fracture line to articular surface

indicating unstable fracture and need to fix

MRI in this displaced lateral condyle fracture shows the

degree of displacement and indicates need to open

reduce

12 Do an arthrogram

Arthrogram delineates articular and fracture surfaces and can help to diagnose the

physeal and intraarticular fractures and assess the articular reduction in a closed

manner

Conclusion

Knowledge of anatomy, normal bony development, and radiographic features of the

pediatric elbow are essential to prompt recognition and treatment of elbow injuries in

children. In most instances, plain radiographs are adequate to detect fractures that

pose a threat to future growth and function. On occasion, additional modalities (eg,

ultrasound, magnetic resonance imaging, or arthrography) are needed to identify and

fully delineate elbow fractures, especially in infants and young children.

I hope that this text will be of help to orthopaedic surgeons to solve the puzzle. If you

are in doubt email your xrays to taralnagda@gmail.com and I will try help you to

arrive at some solution.

Acknowledgements I thank Dr Sandeep Patwardhan (Pune) and Dr Premal Naik (Ahemdabad) –both

well known Pediatric Orthopaedic Surgeons and great friends for some of the cases

used in illustrations.