[Chronic fibular instability of the ankle-joint -- x-ray diagnostic and ligamentous graft (author's transl)].

It was tried to find out how many radiographs are necessary to show instabilities of the ankle-joint with ruptures of the ligamentum talofibulare anterius alone (which is the most common ligamentous lesion) and in combination with other fibular ligaments. Therefore stress views of anatomical speciems of ankle-joints with previous artifically coused lesions were done. It was found that one lateral view with the talus stressed in subluxation and one a.p. view with stressed pes equinus and supination with slight internal rotation of the foot are enough in comparison with the other side. The mostly used plastic reconstructions of old fibular ligament teares by Watson-Jones and Evans act as a tenodesis for the subtalar joint, because the natural anatomical position of the ligamentum calcaneofibulare, which should be replaced, is not respected. We looked for the best positioning of a graft as a replacement of the ligamentum calcaneofibulare by help of a string model in anatomical speciems. Only the straight graft of this ligament gives the best chance of free mobility in the subtalar joint. Other directions of this ligamentous graft lead either to a tenodesis or to an outwear of the graft without a stabilizing effect. Postoperative examinations of nine patients with ligamentous grafts stress this point.