Perilunate fracture-dislocation with scaphoid nonunion and ulnar nerve deficit in a young adult: a case report and review of the literature.

Perilunate fracture-dislocations (PLFDs) are rare but severe wrist injuries. Median nerve involvement is common, whereas ulnar nerve injury is exceptionally rare. Delayed diagnosis remains frequent and negatively impacts outcomes. A healthy 30-year-old man sustained a fall onto his outstretched left hand, presenting with wrist deformity and ulnar sensory deficit. Radiographs showed disrupted Gilula's lines and a scaphoid waist fracture consistent with PLFD. Closed reduction failed, and open reduction with internal fixation via combined volar and dorsal approaches was performed, including carpal tunnel release, scaphoid fixation, ligament repair, and Kirschner wire stabilization. Postoperatively, ulnar sensation improved and carpal alignment was maintained, but scaphoid nonunion developed. The final Mayo Wrist Score was 75. PLFDs with ulnar nerve injury pose diagnostic and therapeutic challenges. Early comprehensive surgical management is essential, though complications may still occur, necessitating long-term follow-up.