How many carpal bones are there and how are they arranged?

There are eight carpal bones arranged in two rows: a proximal row (closer to the forearm) and a distal row (closer to the hand). This arrangement contributes to wrist flexibility and strength.

What are the names of the carpal bones in each row?

The proximal row (lateral to medial) contains: Scaphoid, Lunate, Triquetral, and Pisiform. The distal row (lateral to medial) contains: Trapezium, Trapezoid, Capitate, and Hamate. A common mnemonic is: She Looks Too Pretty. Try To Catch Her.

Which carpal bone is the largest and which is the smallest?

The capitate is the largest carpal bone, with a rounded head on its proximal surface. The pisiform is the smallest, being pea-shaped and acting as a sesamoid bone in the flexor carpi ulnaris tendon.

What is the ossification sequence of the carpal bones?

Carpal bones ossify from a single center after birth in this sequence: Capitate at 2nd month (first), Hamate at end of 3rd month, Triquetral at 3rd year, Lunate, Scaphoid, Trapezium, and Trapezoid around 4th–5th year, and Pisiform at 9th–12th year (last). This timing helps assess skeletal maturity.

What are the key identifying features of the scaphoid and hamate bones?

The scaphoid is boat-shaped with a constriction (waist) and a tubercle on its palmar surface. The hamate is wedge-shaped with a hook-like process called the hamulus on its palmar aspect.

Which carpal bones articulate with the radius and ulna?

The carpal bones articulate with the radius and ulna at the wrist joint. Specifically, the proximal row (scaphoid, lunate, and triquetral) forms these articulations, contributing to wrist movement.

Carpal Bones Anatomy – Names, Arrangement & Mnemonics