Danis–Weber classification

The Danis–Weber classification (often known just as the Weber classification) is a method of describing ankle fractures. It has three categories:

Fracture of the fibula distal to the syndesmosis (the connection between the distal ends of the tibia and fibula). Typical features:
 * Type A
 * below level of the ankle joint
 * tibiofibular syndesmosis intact
 * deltoid ligament intact
 * medial malleolus occasionally fractured
 * usually stable: occasionally nonetheless requires an open reduction and internal fixation (ORIF) particularly if medial malleolus fractured

Fracture of the fibula at the level of the syndesmosis. Typical features:
 * Type B
 * at the level of the ankle joint, extending superiorly and laterally up the fibula
 * tibiofibular syndesmosis intact or only partially torn, but no widening of the distal tibiofibular articulation
 * medial malleolus may be fractured or deltoid ligament may be torn
 * variable stability

Fracture of the fibula proximal to the syndesmosis. Typical features:
 * Type C
 * above the level of the ankle joint
 * tibiofibular syndesmosis disrupted with widening of the distal tibiofibular articulation
 * medial malleolus fracture or deltoid ligament injury present
 * unstable: requires ORIF

Categories B and C imply a degree of damage to the syndesmosis itself (which cannot be directly visualised on X-ray). They are inherently unstable and are more likely to require operative repair to achieve a good outcome. Type A fractures are usually stable and can be managed with simple measures, such as a plaster of paris cast.