Ankle fracture classification: a comparison of reliability of three X-ray views versus two.

Our hypothesis was that malleolar ankle fractures could be classified with two radiographic views as reliably as with three views. Four different observers independently evaluated 99 sets of ankle radiographs. The examiners classified the ankle fractures by using both the Lauge-Hansen and Danis-Weber systems. The interobserver and intraobserver variations were analyzed by kappa statistics. With regard to intraexaminer reliability, the examiners demonstrated excellent accord in classifying the fractures in the Danis-Weber system with either three views or two views. The kappa values were comparable. In the Lauge-Hansen system, three examiners demonstrated excellent accord and one examiner demonstrated good accord in classifying the fractures. Similar kappa values were generated when examiners classified fractures with either three views or two views. With regard to interexaminer reliability, good to excellent accord was demonstrated overall among the four examiners when they used the Danis-Weber system with either three views or two views. The examiners were in good agreement when they used the Lauge-Hansen system. Similar kappa values were generated whether the examiners used three views or two views. Three radiographic views are usually ordered for evaluation of an acute ankle injury. Previous studies have shown that only two views are needed for diagnosis of a malleolar ankle fracture. This study demonstrates that malleolar ankle fractures can be classified with two views, lateral or mortise, with a reliability as good as that achieved with three views. The best agreement is achieved with lateral and mortise views.