thumb|Hamate of the right hand as seen on X-ray (labeled H)
The hamate bone (from Latin , ), or unciform bone (from Latin , ), Latin and occasionally abbreviated as just hamatum, is a bone in the human wrist readily distinguishable by its wedge shape and a hook-like process ("hamulus") projecting from its palmar surface.
Structure
The hamate is an irregularly shaped carpal bone found within the hand. The hamate is found within the distal row of carpal bones, and abuts the metacarpals of the little finger and ring finger.
Adjacent to the hamate on the ulnar side, and slightly proximal and ulnar to it, is the pisiform bone. Adjacent on the radial side is the capitate, and proximal is the lunate bone. The ulnar nerve hooks around the hook of hamate as it crosses towards the medial side of hand.
The hook forms the ulnar border of the carpal tunnel, and the radial border for Guyon's canal. Numerous structures attach to it, including ligaments from the pisiform, the transverse carpal ligament, and the tendon of flexor carpi ulnaris. The said bone does not fully ossify until about the 15th year of life. This condition has been called "Wilson's Wrist".
The calcification of the hamate bone is seen on X-rays during puberty and is sometimes used in orthodontics to determine if an adolescent patient is suitable for orthognathic intervention (i.e. before or at their growth spurt).
Etymology
The etymology derives from the Latin hamatus "hooked," from hamus which means "hook".
Additional images
<gallery>
File:Hamate bone (left hand) - animation01.gif|Position of hamate bone (shown in red). Left hand. Animation.
File:Hamate bone (left hand) - animation04.gif|Hamate bone of the left hand. The hook-like process is called hamulus.
Image:Hamate bone.jpg|Hamate bone.
File:RightHumanAnteriorDistalRadiusUlnaCarpals - Hamate bone.png|Right hand anterior view (palmar view). Thumb on top.
File:RightHumanPosteriorDistalRadiusUlnaCarpals - Hamate bone.png|Right hand posterior view (dorsal view). Thumb on bottom.
Image:Gray219 - Hamate bone.png|Bones of the left hand. Palmar surface. Hamate shown in yellow.
Image:Gray220 - Hamate bone.png|Bones of the left hand. Dorsal surface. Hamate shown in yellow.
Image:Gray422 - Hamate bone.png|Transverse section across the wrist and digits. Hamate shown in yellow.
File:Ospoignet - Hamate bone.png|Cross section of wrist (thumb on left). Hamate shown in red.
File:Slide1dsds - Hamate bone.png|Right wrist joint. Deep dissection. Anterior (palmar) view.
</gallery>
See also
- Carpal bone
- Hypothenar hammer syndrome