Lunate

Lunate is one of the eight small carpal bones in the wrist that are arranged in two rows. The lunate bone is situated in the proximal row of the carpal bones, between the scaphoid bone and the triquetral bone. The lunate bone is named for its crescent shape (lunate comes from the Latin word luna, meaning moon).

Structure

The lunate bone has six surfaces: superior, inferior, volar (palmar), dorsal, lateral, and medial. The superior surface is convex and articulates with the radius bone in the wrist. The inferior surface is deeply concave and forms a part of the carpal tunnel, which houses the flexor tendons and the median nerve. The volar surface is rough and non-articular. The dorsal surface is smooth and convex. The lateral surface articulates with the scaphoid bone, and the medial surface articulates with the triquetral bone.

Function

The lunate bone, along with the other carpal bones, allows for the complex movements of the wrist. It is particularly involved in flexion and extension movements.

Clinical significance

Injuries to the lunate can lead to a condition known as Kienbock's disease, which is characterized by the death of bone tissue due to a lack of blood supply. This can cause pain, swelling, and limited movement in the wrist.

See also

• Carpal bones
• Wrist
• Kienbock's disease