Operative treatment of ankle fractures.

In an unselected prospectively planned series of 611 ankle fractures 25% were of the AO (Weber) type A, 56% type B and 13% type C; 4% were impact fractures. The fractures were also classified according to Lauge Hansen's system, which was considered more complicated and not suitable for planning of operative treatment. Lauge Hansen's theory of the mechanism of the supination-eversion (SE) injury is questioned--outward rotation does not seem to be obligatory for the typical SE injury. 345 fractures were operated on, and 327 (95%) of them were followed up 1-6 years after operation. The range of motion was measured as loaded dorsal extension (normal value 33 degrees) and loaded plantar flexion (normal value 45 degrees). The clinical results were "excellent" to "good" for 81% of the dislocation fractures, 38% of the impact fractures and for two of the six combined shaft/ankle fractures. In 14% of the dislocation fractures and 50% of the impact fractures posttraumatic arthritis developed. There was a significantly higher degree of arthritis among the patients with a posterior articular surface bearing fragment. There was also a strong correlation between the degree of arthritis and poor clinical results. The clinical and radiographic results from use of the AO (ASIF) method were better than those of conservative treatment or other operative methods. According to an AID analysis the most important factors for the final outcome were: 1) type of fracture, 2) accuracy of operative reduction and 3) the patient's sex.