Age / Sex : 34 / M

Chief complaint : Right wrist pain, onset 2 months ago

What is your diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).


Courtesy : 홍석주 (Suk-Joo Hong), 고려대 구로병원 (Korea Univ. Guro Hospital)

Midcarpal dislocation, lesser arc injury

Discussion

Findings:

 PA view: Loss of normal carpal arc relationship and scapholunate, lunotriquetral joint spaces

 Lateral: volar radiolunate subluxation, dorsal subluxation of capitate

Differential Diagnosis:

 Perilunate dislocation

 Lunate dislocation

Discussion:

 Mayfield stage of Perilunate instability, Lesser arc injury

: Sequence as the ligaments around the lunate fail in a radial to ulnar direction

• Stage I – SLL tear with SL dissociation, rotatory subluxation


• Stage II – Capitate dorsal dislocation + Dissociation of lunocapitate joint (perilunate dislocation)


• Stage III – LTL fail, lunate separated from triquetrum (midcarpal dislocation)


• Stage IV – Capitate migrates proximally, complete dislocation of lunate (lunate dislocation)

References:

1. Sonin A. et al. Carpal dislocation. In Diagnostic Imaging. Musculoskeletal: Trauma. Amirsys Inc. 2010;4-60-65