Imaging (Ossification Centres)


1 year

Radial head

3 years

Internal (medial) epicondyle

5 years


7 years


9 years

Lateral (External)

11 years

There are six ossification centres in the elbow of a developing child and they occur in a fixed order at sequential times up to the age of 13 years, although these times are variable.

It is the presence of these centres that make paediatric elbow x-rays notoriously difficult to interpret. Knowledge of these ossification centres and the age at which they appear will assist the observer in identifying whether a fracture is present or not.

A well known helpful pneumonic for this is CRITOL or CRITOE.

Note that these ages vary but a broad guide of 1,3,5,7,9 and 11 years is easy to remember.