Fracture or a normal ossification center?

This is a common question heard when viewing an xray of a pediatric elbow. How do you remember the timing of normal ossification centers? FYI, the xray images above are normal and have no fractures.

Trick of the Trade

The mnemonic CRITOE 1-3-5-7-9-11

  • Age 1 year: Capitellum
  • Age 3 years: Radial head
  • Age 5 years: Internal (medial) epicondyle
  • Age 7 years: Trochlea
  • Age 9 years: Olecranon
  • Age 11 years: External (lateral) epicondyle

This great video is from a relatively new YouTube channel that I stumbled upon called “Radiology Channel“, which is a project featuring short polished presentations by Dr Andrew Dixon, Dr Frank Gaillard and Dr Jeremy Jones.

Michelle Lin, MD
ALiEM Editor-in-Chief
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg San Francisco General. Founder of ALiEM @aliemteam #PostitPearls
Michelle Lin, MD