Dislocations of bones of the hand

[Mary Mallozziberg]

The bones at the base the hand (carpal bones), usually the lunate or the capitate, move out of their normal position.

These dislocations usually occur when great force is applied to the wrist and it is bent backward.
The wrist and hand are painful and may look misshapen, and people cannot move them normally.
Symptoms and the circumstances of the injury suggest the diagnosis, but doctors take x-rays to confirm it.
Doctors manipulate the bones back in place without making an incision, apply a splint, and refer people to an orthopedist because surgery is often needed.

(See also Overview of Dislocations.)
The carpal (wrist) bones are located at the base of the hand, between the forearm bones (radius and ulna) and the long metacarpal bones of the hand. There are eight small carpal bones.
Two of the carpal bones are commonly dislocated:

The capitate (which is the largest bone in the hand, located in the middle of the lower palm)
The lunate (which is located between the capitate and the end of the ulna)

Dislocation of the capitate is called a perilunate dislocation. Perilunate dislocations are more common than lunate dislocations.
These dislocations result from great force that causes the wrist to bend backward, usually a fall on an outstretched hand or an injury in a car crash.