Lunate, dislocation

In complete dislocations of the lunate, the displacement is usually in a palmar direction. The greater force required to produce this injury is responsible for massive disruption of both the dorsal and palmar ligaments.

There is also a disruption of the dorsal radiolunotriquetral ligament complex.

The capitate displaces proximally towards the distal radial articular surface. A lateral radiograph shows the “spilled teacup” configuration of the lunate.
On the AP view, the displaced lunate has a triangular profile, rather than its normal quadrilateral image.