Roughly one center appears per year from the age of 1 year to 7 years, anti-clockwise in right hand and clock-wise in left hand looking from the anterior surface, i.e. from ulnar side to radial side. Pisiform, being a sesamoid bone it gets left behind and only develops years later.
- capitate: 1-3 months
- hamate: 2-4 months
- triquetrum: 2-3 years
- lunate: 2-4 years
- scaphoid: 4-6 years
- trapezium: 4-6 years
- trapezoid: 4-6 years
- pisiform: 8-12 years
Also it’s nice to know the appearance of ossification center of:
- Distal radius: 1 year
- Distal ulna: 4-5 years
A video mnemonic:
If this visual mnemonic doesn’t help you, here’s another mnemonic to help you remember.
Camera Has Three Lens, So Take Three Photos.
- Capitate
- Hamate
- Triquetral
- Lunate
- Scaphoid
- Trapezium
- Trapezoid
- Pisiform
Also, if you’ve been having hard time remembering if the location of trapezium and trapezoid, just remember that the trapeziUM is towards thUMb and trapezoID is insIDe.