How we do it? Trimalleolar Fractures: Posterolateral Approach for Fixing the Syndesmotic Ligament, Posterior Malleolus, and Fibula

Introduction: Syndesmotic injury in trimalleolar fracture is necessary to address intraoperatively by stability test, as it affects post-operative functional outcomes. Most of syndesmotic injuries are stable after fixation of the posterior malleolus, but in rare cases, syndesmosis is not stable after adequate fixation. In those rare conditions, we have to fix syndesmosis by corticocancellous (CC) screw throw lateral fibula plate. We emphasize this complex problem and offer solutions to overcome it. Case Report: Case 1: A 45-year-old male suffered significant trauma to his right ankle from a slip and fall, resulting in a trimalleolar fracture. The open reduction and internal fixation (ORIF) throw posterolateral approach was performed after wrinkles were seen on the ankle. A four-hole Ellis plate was used in antiglide mode to reduce posterior malleolar fragments. The lateral malleolus is fixed with a 7-hole, 1/3-locking tubular plate with a tricortical syndesmotic CC screw. The medial malleolus was internally fixed by a 6-hole LC-DCP. Case 2: A 49-year-old female suffered significant trauma to her right ankle from a domestic fall, resulting in a trimalleolar fracture. The ORIF throw posterolateral approach was performed after wrinkles were seen on the ankle. A four-hole Ellis plate was used in antiglide mode to reduce posterior malleolar fragments. The lateral malleolus is fixed with an 8-hole, 1/3-locking tubular plate with a tricortical syndesmotic CC screw. The medial malleolus was internally fixed by a 2 CC screw with an 8-hole LC-DCP. The anterior distal tibia fragment was fixed with a 16-mm anteroposterior CC screw. Conclusion: In a trimalleolar ankle fracture, fixation of the posterior malleolus is important for a better post-operative functional outcome, irrespective of the size of the posterior malleolus. The author recommends lateral fibula plate fixation by creating a window between the skin and the peroneus longus and brevis tendon, so we have a chance to put a syndesmotic screw into the lateral plate if syndesmosis is not stable. Keywords: Trimalleolar ankle fracture, syndesmotic injury, posterolateral approach, ORIF.