Lauge-Hansens classification system and Webers classification system are the two most commonly used systems in ankle fractures. both are based on causative mechanism but both have some deficiencies. Authors intended to decide which is easily applicable in clinical practice and shwich provides more information about treatement, especially that of diastasis.

So we analysed 143 cases of ankle fractures in Seoul National University Hospital, Kang-nam General Hospital and Namseoul Hospital from January 1983 to December 1988.

The results obtained are as follows.

1. Webers type A fractures correspond not only supination-adduction but also to pronation-abduction and pronation-dorsiflexion. Type B fractures correspond most closely to supination-external rotation and possibly to pronation abduction and pronation external rotation. Type C fractures show the nearest equivalence to pronation-external rotation and occasionally correspond to supination-external roation or pronation-abduction.

2. Diastasis was noted in 16 cases(28%) of type B and in 18 cases(74%) of type C and this lower incidence was seemed to be due to neglect of diastasis at physical examination or during operation.

3. It seemed to be more reasonable to fix the diastasis with tibiofibular fixation screw especially in type C.

4. Webers simpler classification system, which can explain the hidden ligamentous injury such as diastasis, was more easily applicable in daily use than Lauge-Hansen classification.