Danis Weber classification in based on the level of the fibular fracture. A fibular fracture that is more proximal indicates an increased risk of syndesmotic disruption and ankle instability. There are 3 types of Danis Weber classification, and they are type A, type B, and type C.
Type A fracture is an internal rotation and adduction injury. It is a fracture of the fibula below the level of the tibial plafond. Additionally, there is usually an avulsion injury from supination of the foot. It may also be associated with oblique or vertical medial malleolus fracture. With this type of fracture, syndesmotic disruption is rare, but can occur. Finally, the type A Danis Weber fracture resembles the supination/adduction injury in Lauge-Hansen classification.
Type B fracture is an external rotation injury. It is an oblique or spiral fracture of the fibula near or at the level of the syndesmosis. Type B fractures may be associated injury to the medial structures or the posterior malleolus. Also, about 50% of these fracture include syndesmotic injury. In relation to the Lauge- Hansen classification, the type B Danis fracture resembles most closely the supination/external rotation injury.
Type C fracture is an abduction injury. It is a fracture above the level of the syndesmosis, and therefore syndesmosis disruption always occurs. There is also almost always an associated medial injury. This type of fracture includes Maisonneuve fracture pronation/abduction or pronation/external rotation. In relation to the Lauge-Hansen classification, type C Danis Weber fractures simulate an abduction/external rotation injury.
