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:[1]

Type A

Danis–Weber classification of ankle fractures (Types A, B and C)

Danis–Weber classification on X-ray.

Fracture of the lateral malleolus distal to the syndesmosis (the connection between the distal ends of the tibia and fibula). Typical features:

• 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

Type B

Fracture of the fibula at the level of the syndesmosis. Typical features:

• 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

Type C

Fracture of the fibula proximal to the syndesmosis. Typical features:

• 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.