The Weber Classifications of Ankle Fractures

C.S. Haw, Orthopaedic Surgeon

There are two recognised classifications of ankle fractures in Orthopaedic texts. The first classification was by Lauge Hansen that was developed in 1942 and this classification was based on experimental cadaveric studies. Its main value was in correlating the radiographic features of the fracture with the original deforming force and hence indicating the way in which the fractures should be reduced. This was more important for the era in which these fractures were treated conservatively. The Weber classification which was developed in 1972 was developed in association of the advent of the use of internal fixation. The Weber classification did not take into account the mechanics of the injury but was a simple anatomic classification according to the location of the fracture in the fibula. Nevertheless a Weber 'A' fracture is essentially caused by inversion, a Weber 'B' is an external rotation pronation fracture and a 'C' is a pure eversion injury that is also called a Dupuytrens fracture. The Weber 'B' category involves a significant disturbance of the inferior tibiofibular joint in 50% of cases. The Weber 'C' always involves the disruption of the inferior tibiofibular joint and a Weber 'A' never involves a disruption of the inferior tibiofibular joint.

The Weber classification has the criticism of not being comprehensive in the description of ankle fractures but has the value of simplicity and also there is little observer variation in the classification of ankle fractures using the Weber method in contrast to the Lauge Hansen method in which fractures are poorly duplicated by different observers. One other point possibly in favour of utilising the Weber classification is that attention is drawn to the fibular and it is a fairly true statement of fact that if the fibular anatomy is restored, particularly fibular length and if the inferior tibiofibular joint is restored then 99% of ankle fractures will be perfectly reduced. Finally there has been some swing back to a simple classification of ankle fractures as uni-malleolar, bi-malleolar fractures or tri-malleolar fractures.