A variant of perilunate dislocation: A case report and literature review

Perilunate dislocation is a rare carpal dislocation, which are predominantly trans-styloid and trans-scaphoid. This type of fracture dislocation is seen due to axial loading of a hyperextended ulnar-deviated wrist. This can result in the disruption of the scapholunate, lunocapitate, and lunotriquetral ligaments. The lunate may dislocate volar or dorsal to the other carpal bones. Herein, we have reported a case of trans-styloid, trans-scaphoid perilunate fracture dislocation with carpal tunnel syndrome, which has never been reported in the literature. A 38-year-old construction worker presented with a swollen hand and signs of carpal tunnel syndrome. The patient was diagnosed with perilunate fracture dislocation after a through clinical and radiological assessment. The scaphoid had invaginated into the radial styloid and demonstrated a comminuted fracture pattern. Volar lunate displacement was identified, and the patient demonstrated signs of carpal tunnel syndrome, which is not a common presentation. Open reduction with ligament repair was performed to minimize jeopardizing the hand function. Spelt tea cup sign is a diagnostic for perilunate dislocation. Operative exploration and reduction is imperative for failed closed lunate dislocation reduction to minimizes ongoing soft tissue jeopardy. Moreover, carpal tunnel release is indicated in the present of symptomatic carpal tunnel syndrome. To our knowledge, only a few cases of trans-styloid, trans-scaphoid perilunate dislocation with neurological deficit have been reported.