Maisonneuve fracture involves fracture of the proximal fibula associated with an occult and unstable injury of the ankle. The problem in these patients occur when the ankle injury is presented without a fracture of the lateral malleolus, or the medial malleolus and the injury is mistakenly diagnosed as an ankle sprain and the proximal fibular fracture is missed. Examine the leg for tenderness in the proximal fibula to diagnose a proximal fibula fracture. The patient could be mistakenly treated for having an isolated proximal fibular fracture alone and the ankle injury is missed.
High index of suspicion is necessary to diagnose and treat this injury. Maisonneuve fracture equals syndesmotic injury. Syndesmotic Injury equals Syndesmotic Reduction and Fixation. If ankle x-rays show medial or posterior malleolus fracture, or a medial clear space widening with no fracture of the lateral malleolus, then you must obtain a long-leg films to assess possible proximal fibular fracture. Clinical examination of their entire leg for pain and tenderness in addition to long leg films of the entire leg that includes the ankle, and the knee is mandatory in case of the patient with approximate fibular fracture to exclude the presence of an additional ankle injury, or if the patient has an unexplained increase in the medial clear space of the ankle joint. You should be searching for the presence of a high fibular fracture. Look for signs of syndesmotic injury such as an unexplained increase in medial clear space or tibiofibular clear space is widened and it should be less than 5 millimeters.
So how do you explain this injury? It is explained by the presence of rotation force to the ankle with transmission of the force through the interosseous membrane, which exits through a proximal fibular fracture. Maisonneuve fracture occurs from external rotation of the foot, most often with pronation mechanism. This force has to go somewhere! If you don’t see a fracture of the fibula then do the squeeze test or the external rotation stress test (both will show syndesmotic). The injury can involve the deltoid ligament injury or medial malleolar fracture medially and a fibular fracture proximally. Additionally, the tibiofibular ligaments are also involved, which can be the anterior tibiofibular ligament, interosseous ligament, the posterior tibiofibular ligament or posterior malleolar fracture. This looks like a very unstable ankle injury that may not be very obvious at presentation and you have to look out for it.
So how do you treat an Maisonneuve Fracture? This treated by fixation of the tibiofibular syndesmotic injury (key of treatment) or syndesmotic screws. if you have a medial site injury and there is a tear of the deltoid ligament, leave it alone. if there’s a medial malleolus fracture you should fix that of the lateral side if there’s approximate fibular fracture leave it alone. If there is a medial malleolar fracture, it should be fixed. If there is a proximal fibular fracture on the lateral side, leave it alone. As for the Syndesmotic Injury, the fixation has to be stable and adequate. Because of the magnitude of the injury, the Maisonneuve fracture may require more syndesmotic screws than with a routine ankle fracture with syndesmotic injury. After the fixation you will give a short leg non-weight bearing splint for six to eight weeks. Here is a patient taste example: the proximal fibular fracture and you can see increase in the medial clear space and you can see that the syndesmosis is widened. You can see that in the posterior malleolar fracture the patient is fixed with syndesmotic screws.