thumb|Lunate of the right hand on X-ray (labeled L)
The lunate bone (semilunar bone) is a carpal bone in the human hand. It is distinguished by its deep concavity and crescentic outline. It is situated in the center of the proximal row carpal bones, which lie between the ulna and radius and the hand. The lunate carpal bone is situated between the lateral scaphoid bone and medial triquetral bone.
Structure
The lunate is a crescent-shaped carpal bone found within the hand. The lunate is found within the proximal row of carpal bones. Proximally, it abuts the radius. Laterally, it articulates with the scaphoid bone, medially with the triquetral bone, and distally with the capitate bone. The lunate also articulates on its distal and medial surface with the hamate bone.
Blood supply
The lunate receives its blood supply from dorsal and palmar branches.
Function
The carpal bones function as a unit to provide a bony superstructure for the hand.
Clinical relevance
thumb|Perilunar dislocation as seen on X-ray (right upper limb).
The lunate bone is the most frequently dislocated carpal bone. For its diagnosis, a little-known depression on the dorsal aspect of the wrist, known as the lunate foveola, is used. <!--from http://www.wheelessonline.com/ortho/lunate -->
- Carpal coalition
- Kienbock's disease
- Teisen classification
Etymology
The name of the lunate bone derives from the "crescent-shaped" (), from Latin luna ("moon"), from the bone's resemblance to a crescent moon. In amphibians and reptiles, the bone is instead referred to as the intermedium, because of its position between the other two proximal carpals.
Additional images
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File:Lunate bone (left hand) - animation01.gif|Lunate bone of the left hand (shown in red). Animation.
File:Lunate bone (left hand) - animation02.gif|Lunate bone of the left hand. Close up. Animation.
Image:Lunate bone.jpg|Lunate bone.
Image:Gray219 - Lunate bone.png|Bones of the left hand. Volar surface.
Image:Gray220 - Lunate bone.png|Bones of the left hand. Dorsal surface.
File:Ospoignet - Lunate bone.png|Cross section of wrist (thumb on left). Lunate shown in red.
Image:LunatedislocationAP.jpg|Dislocated lunate
Image:LunatedislocationL.jpg|Dislocated lunate
File:Dissection of the human hand - 02.jpg|Wrist joint. Deep dissection. Posterior view.
File:Slide5kaka.JPG|Wrist joint. Deep dissection. Posterior view.
</gallery>
See also
- Carpal bone