Pisiform bone Pisiform bone The pisiform bone ( or ), also spelled pisiforme (from the Latin "pisifomis", pea-shaped), is a small knobbly, sesamoid bone that is found in the wrist. It forms the ulnar border of the carpal tunnel. The pisiform is a sesamoid bone, with no covering membrane of periosteum. It is the last carpal bone to ossify. The pisiform bone is a small bone found in the proximal row of the wrist (carpus). It is situated where the ulna joins the wrist, within the tendon of the flexor carpi ulnaris muscle. It only has one side that acts as a
Hamate bone of the hand. The ossification of the hamate starts between 1 and 12 months. The hamate does not fully ossify until about the 15th year of life. The bone is also found in many other mammals, and is homologous with the "fourth distal carpal" of reptiles and amphibians. The carpal bones function as a unit to provide a bony superstructure for the hand. The hamate bone is the bone most commonly fractured when a golfer hits the ground hard with a golf club on the downswing or a hockey player hits the ice with a slap shot. The fracture is