In a series of 146 displaced ankle fractures, the effects of age, sex, side of injury, mechanism of injury, severity as determined by the Lauge-Hansen classification, type of injury (open or closed), open or closed treatment, and internal fixation of one or both malleoli were analyzed using subjective, objective, and radiographic parameters. Statistically significant prognostic features were identified and a prognostic scale was developed using multiple linear-regression analysis.

The significant parameters were age, adequacy of the post-reduction positions of the medial and lateral malleoli, and completeness of the restoration of the deltoid ligament and distal tibiofibular syndesmosis. Open reduction proved superior to closed reduction, and in bimalleolar fractures open reduction of both malleoli was better than fixing only the medial side. Using the data on the first 109 fractures, a multiple linear-regression equation was formulated and used to predict the outcomes of the last thirty-seven fractures in the study. The accuracy of the predictions in them was 81 per cent.