The secondary ossification center for the lateral epicondyle of the humerus appears and fuses at approximately which age (mnemonic: CRITOE sequence)?
- A Appears at approximately 1 year; the first to appear in the sequence
- B Appears at approximately 11 years; fuses last (after 14–16 years) in the CRITOE sequence ✓
- C Appears at approximately 5 years; fuses at approximately 10 years
- D Appears at approximately 8 years; fuses synchronously with the medial epicondyle
Explanation
The CRITOE mnemonic describes elbow ossification centers and their approximate ages of appearance (years): Capitulum (1), Radial head (3), Internal (medial) epicondyle (5), Trochlea (7), Olecranon (9), External (lateral) epicondyle (11). The lateral epicondyle is the last to appear and fuses with the distal humerus in the mid-teens. Importantly, the medial epicondyle is an avulsion injury risk in Little Leaguer's elbow; if a trochlear center is visible without a medial epicondyle center, the medial epicondyle has been avulsed into the joint. CRITOE helps radiologists identify avulsed or unfused apophyses.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.