Perilunate dislocation

Case contributed by Dr Henry Knipe

Presentation

Fall from height.

Patient Data

Age: 60 years
Gender: Male
Modality: X-ray

The lunate is "pie-shaped" on the frontal and oblique projections, and there is dislocation of the lunocapitate articulation on the lateral with dorsal displacement of the distal carpal row. Radiolunate articulation has been maintained. 

Modality: CT

Palmar angulation of the lunate with dislocation of the lunocapitate articulation; the radiolunate articulation is maintained. Dorsal displacement of the distal carpal row compared to the distal radius. 

Multiple small bony loose bodies are identified within the wrist joint, several of which are tiny and surround the lunate bone and are likely acute. Avulsed fracture of the ulnar styloid process. Diffuse joint effusion and soft tissue oedema. 

Case Discussion

Recognising carpal dislocations is important because of the potential complications, including median nerve compression in the carpal tunnel. Distinguishing perilunate dislocations from lunate dislocations can be tricky, but key points are:

  • in perilunate dislocations, the radiolunate articulation is maintained and the distal carpal row is dorsally displaced compared to the radius
  • in lunate dislocations, there is disruption of both lunocapitate and radiolunate articulations, with normal alignment of the distal carpal row with the radius
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Case Information

rID: 50834
Case created: 23rd Jan 2017
Last edited: 26th Apr 2017
Inclusion in quiz mode: Included

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