Junior call case 3

Trans-scaphoid perilunate dislocation.

Evaluation of wrist involves inspecting at the carpal arcs (also known as galula lines). These lines should be smooth – otherwise suspect carpal dislocation.

• The lunate, in particular, can sometimes appear “pieshaped”, suggestive of a lunate or perilunate dislocationLateral view x-ray will clarify this differential.

o Lunate dislocation = Lunate is not in line with the radius (anteriorly positioned). Capitate remains in line with the radius.

o Perilunate dislocation = Lunate remain in line with the radius. Capitate is not in line with the radius (posteriorly positioned).

• Two complications of scaphoid fractures include AVN and non-union. For scaphoid fractures, the blood supply runs from distally to proximally. Therefore, proximal fragment necroses first.

o Always comment on the appearance of the proximal pole for all scaphoid fractures.

• There is a mechanistic high association between a lunate/perilunate dislocation and scaphoid fracture. When you see one, look for the other!

Accession: CL0754

Study description: Upper Extremity