The Maisonneuve fracture is a spiral fracture of the proximal third of the fibula associated with a tear of the distal tibiofibular syndesmosis and the interosseous membrane. There is an associated fracture of the medial malleolus or rupture of the deep deltoid ligament of the ankle. This type of injury can be difficult to detect. The Maisonneuve fracture is typically a result of excessive, external rotative force being applied to the deltoid and syndesmotic ligaments. Due to this, the Maisonneuve fracture is described as a pronation-external rotation injury according to the Lauge-Hansen classification system. It is also classified as a Type C ankle fracture according to the Danis-Weber classification system. The Maisonneuve fracture is similar to the Galeazzi fracture in the sense that there is an important ligamentous disruption in association with the fracture. The fracture is named after the surgeon Jules Germain François Maisonneuve. Cause Forceful, external rotation of the ankle joint is the main cause of a Maisonneuve fracture. Engaging in high-intensity sports or falling over can increase the risk of tearing the deltoid ligament or cause an avulsion fracture of the medial malleolus from external rotation of the foot. In some cases, motor vehicle accidents can also result in a Maisonneuve fracture. Signs and symptoms Common symptoms of a Maisonneuve fracture are pain, swelling, tenderness, and bruising around the ankle joint and inferior (or distal) tibiofibular joint. More specifically, as a pronation-external rotation injury, pain during external rotation of the ankle joint is expected. Additionally, there is a reduced range of motion of the foot and an inability to weight-bear due to ankle pain. Pain may also be felt around the medial and lateral aspects of the ankle, and more rarely around the superior (or proximal) tibiofibular joint. Damage to the deltoid ligament or interosseous membrane can cause haemorrhaging around the surrounding tissues, resulting in a localised oedema. As the syndesmotic ligaments are responsible for stabilising the ankle mortise and tibiotalar joint, disruption to this syndesmosis can cause a reduction of the space between the distal tibia, fibula, and talus. A long-term effect of this is painful ankle osteoarthritis due to the direct contact between the tibia and talus. If a Maisonneuve fracture is left untreated, instability of the tibiotalar joint and deltoid ligament can cause a valgus deformity of the ankle. This leaves the ankle joint in a state of chronic pronation, characterised by a protrusion