Traumatic Volar Dislocation of a Hemi-Scaphoid-Lunate Complex across the Carpal Ligament: A Case Report.

INTRODUCTION: Palmar trans-scaphoid-lunate dislocation with proximal migration of the fragment complex is an exceedingly rare carpal injury whose management is not standardized. We report a case of extreme proximal volar dislocation of a hemi-scaphoid and lunate complex displaced approximately 5 cm from its anatomical location. CASE REPORT: A 16-year-old right-handed male sustained a closed injury to his left wrist after falling from a one-story building. He underwent surgical fixation 2 weeks after injury, once soft-tissue swelling had settled sufficiently for open reduction. Neurovascular examination was normal, but wrist mobility was limited and a 3 × 3 × 2 cm mass was palpable in the volar forearm. Radiographs and computed tomography revealed a volar trans-scaphoid perilunate fracture-dislocation with the lunate and proximal scaphoid migrated into the forearm. The fragments were mobilized through a volar approach and reduced anatomically through a dorsal 3-4 carpal approach. The scaphoid was stabilized with a Herbert screw and the lunate with three Kirschner wires. At 12 months, imaging raised concern for osteonecrosis of the scaphoid and lunate without arthritic change. At 3-year follow-up, the patient was pain-free with improved wrist motion, a disabilities of the arm, shoulder, and hand score of 7.5, and mild degenerative radiocarpal change but no loss of carpal height. CONCLUSION: Combined volar and dorsal reduction and fixation of a severely displaced hemi-scaphoid-lunate complex can achieve good mid-term functional results despite early radiographic features suggestive of osteonecrosis, though long-term surveillance remains necessary.