LAUSR

Abstract Rationale: Radiocarpal fracture-dislocations are extremely infrequent injuries caused by high-energy trauma and involve significant osseous and ligamentous injuries. If not treated properly, it can lead to serious complications such as ulnar translation of the carpus, multidirectional instability, loss of motion, and post-traumatic arthritis. Purely ligamentous injuries are rarer than fracture-dislocation injuries. Because previous studies have reported small patient cohorts, there has been no standardized treatment strategy for purely ligamentous radiocarpal dislocation. Patient concerns: A 24-year-old man suffered a left wrist injury in a motorcycle accident. Plain radiographs revealed dorso-ulnar radiocarpal dislocation without radial fracture and Carpal-ulnar distance ratio (CUDR) was 0.16. MRI scans showed the disruption of the dorsal ligaments and capsules and avulsed from the proximal insertion of the volar radiocarpal ligaments. Diagnosis: Dorsoulnar radiocarpal dislocation with purely ligamentous injury. Intervention: We removed the interposing chondral fragment from the radiocarpal joint and repaired the radioscaphocapitate (RSC) and radiolunate (RL) ligaments with the Jugger Knot Soft Anchor Suture (Biomet, Inc, Warsaw, IN) and applied additional radiocarpal K-wires and an external fixator to maintain reduction and optimal ligament tension. Outcomes: The patient showed good clinical results although ulnar translation of the carpus recurred in radiological follow-up. Lessons: Aggressive surgical management is needed earlier in the treatment of purely ligamentous radiocarpal dislocation, especially if the ulnar translation of the carpus was observed in the initial radiographs.