Children's ankle fractures. Classification and epidemiology.

In an investigation of childhood and adolescence fractures (age groups 0-16) occurring in Malmö during 1950, 1955, 1960, 1965, 1970 and 1975-79, a total of 8682 were found. Four per cent or 373 ankle fractures were classified according to their roentgenological appearance. Avulsion fractures of the tip of the lateral malleolus were the most frequent, followed by fractures involving the distal fibular physis. Triplane and Tillaux fractures were the third and fourth most common fracture groups. Tillaux fractures were more common in girls (0.01 greater than P greater than 0.001). There was no statistically significant difference between the sexes in the other fracture groups or in the whole series. Most injuries were caused by low energy trauma. A foot caught in a bicycle wheel resulted more often in an epiphyseal fracture of the lateral malleolus than any other type of fracture. Otherwise no other etiological factor caused a significant number of cases in any fracture group. There was a seasonal variation with twice as many fractures during April and September as compared with July and December. The incidence showed a steady increase during growth which ceased after the early teens due to a lower incidence among girls in the age groups 15-16. The incidence increased significantly during the 30 years covered by this study.