The pisiform bone's unique anatomical position and late ossification present an evolutionary puzzle.
Existing theories on the pisiform's origin include sesamoid development, polydactyly, and variations in pentadactyl hand evolution.
Purpose:
To review and evaluate existing theories regarding the evolutionary origin of the human pisiform bone.
To present the most plausible theory for the pisiform's development within the carpus.
Summary:
The pisiform bone is an unusual carpal bone, located anteriorly and within the flexor carpi ulnaris tendon.
The most likely theory suggests the pisiform originated from the central carpal series of a 12-bone ancestral carpus, with medial displacement of an ulnar element.
Impact:
This research clarifies the evolutionary trajectory of the human carpus.
Understanding the pisiform's origin contributes to a comprehensive model of human skeletal evolution.