Carpal bones - Fracture, Age determination, Ossification & mnemonics

Medico Feeds October 05, 2020

Carpal bones:

The carpus (carpus = wrist) contains 8 carpal bones which are arranged in two rows, proximal and distal rows.


Proximal row:

  - Scaphoid
  - Lunate
  - Triquetral
  - Pisiform

Distal row:

   - Trapezium
   - Trapezoid
   - Capitate
   - Hamate

(Note: In Anatomical position, Lateral to Medial)

Mnemonic for Carpal bones:


“She Look Too Preety Try To Catch Her”

She   -    Scaphoid
Look   -   Lunate
Too   -   Triquetral
Preety   -  Pisiform
Try   -   Trapezium
To   -   Trapezoid
Catch  -  Capitate
Her   -  Hamate


Ossification:

It is important for determining the age especially in medico-legal cases. The year of appearance of centre of ossification in
the carpal bones as follows,


Capitate  -  Second month
Hamate  - End of third month
Triquetral  - Third year
Lunate,Scaphoid  -  4 yrs in 🚹,6 yrs in 🚺
Trapezium & Trapezoid
Pisiform  - 12 yrs in 🚺,9 - 10 yrs in 🚹

(The Capitate is the first bone to ossify and Pisiform is the last bone to ossify).

Fractures:

1.Fractures of Scaphoid is quite common. Scaphoid fractures occurs,when fallen from the height with outstretched hands.
It causes swelling and tenderness in Anatomical Snuff Box, thumb and index finger. Pain is usually felt in the Anatomical Snuff Box.


2. Dislocation of Lunate is produced by fall with dorsiflexed hand. It causes compression of median nerve leading to Carpel Tunnel Syndrome (Ape-like deformity of the hand).


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