The order of appearance of secondary ossification centres around the elbow can be remembered by the mnemonic CRITOE. What does the 'O' in CRITOE represent, and at what approximate age does it appear?

• A Olecranon — appears at 10 years ✓
• B Outer (lateral) epicondyle — appears at 11-12 years
• C Olecranon — appears at 6 years
• D Outer (lateral) epicondyle — appears at 6 years

Explanation

CRITOE stands for Capitellum (1 year), Radial head (3 years), Internal (medial) epicondyle (5 years), Trochlea (7 years), Olecranon (9-10 years), External (lateral) epicondyle (11 years) — each appearing approximately 2 years apart. The olecranon centre ('O') appears around 9-10 years of age. This sequence is forensically and radiologically important: an apparent 'trochlea' ossification centre without a visible medial epicondyle centre should raise suspicion that the medial epicondyle has been avulsed and entrapped in the joint (since the medial epicondyle must appear before the trochlea).

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.