or carpal ligamentous injury stage II – best viewed on the lateral view of the wrist
Normally, you can see 3 C’s as the lunate (cup)”sits” on the articular surface of the radius (plate), and the capitate (apple) “sits” on the articular surface of the lunate.
With perilunate dislocation:
– the capitate is posteriorly dislocated
– the lunate remains articulated with the radius
– on the PA view, the capitolunate joint space is lost as the bones overlap each other, and the 3 arcs formed by the carpal bones are disrupted
This injury can be associated with:
– scaphoid fracture (transscaphoid perilunate dislocation)
– ulnar styloid fractures
– capitate fracture (transscaphoid transcapitate perilunate dislocation)
– median nerve injury
ED management is closed reduction and immobilization in a long arm splint. They need urgent (same day) Orthopaedics referral for reduction / repair.