UMEM Educational Pearls

Title: What's the Diagnosis? Case by Dr. Bennett Myers

Posted: 7/21/2014 by Haney Mallemat, MD (Updated: 7/22/2014)
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Question

45 year-old right-hand dominant patient presents with right hand pain from a prior injury to hand. Patient has also been injecting subcutaneous heroin into hand for relief. What's the diagnosis?

Answer

Perilunate dislocation (volar displacement)...and severe hand cellulitis.

Perilunate and Lunate dislocations

Lunate dislocation: normal alignment of the distal radius, carpels, and metacarpals; the lunate is displaced
Perilunate dislocation: lunate will demonstrate normal alignment and the remainder of the carpels and metacarpals will typically be displaced in a dorsal direction (occasionally in a volar direction as in this case)
These dislocations occur following high-energy trauma, typically with a hyperextended and ulnar deviated hand
Plain films are usually enough to make diagnosis, but CT may be used to assess for associated occult fractures (e.g., diagnose co-existing scaphoid fracture

References

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