Os triquetrum

The triquetral bone also called triquetrum, pyramidal, three-faced, and formerly cuneiform bone) is located in the wrist on the medial side of the proximal row of the carpus between the lunate and pisiform bones.

It is on the ulnar side of the hand, but does not articulate with the ulna.

It connects with the pisiform, hamate, and lunate bones.

It is the 3rd most commonly fractured carpal bone.