Arthrographic differential diagnosis between ruptures of the anterior talofibular ligament, the joint capsule and the anterior tibiofibular ligament.

From literature study, surgical findings and cadaver experiments, it is unlikely that, in an inversion type ankle sprain, rupture of the anterior tibiofibular ligament frequently accompanies rupture of the capsule and the lateral ligaments. Contrary to the experience of other authors, we found the presence or absence of a) a contrast-free zone, b) the tibiofibular recess, or c) both together, on ankle arthrography in no way indicative of a rupture of the anterior tibiofibular ligament. Contrast leakage out of the joint into the soft tissues without leakage below and lateral to the lateral malleolus indicates rupture of the joint capsule. Leakage below and lateral to the lateral malleolus indicates rupture of the anterior talofibular ligament. The anatomic relationships between the syndesmosis, the joint capsule, the tibiofibular recess and the anterior talofibular recess and the anterior talofibular ligament were studied on cadavers and during surgery. Contrast spread in the soft tissues is probably determined by the arrangement of and damage to the soft tissues and by the size of the haematoma and follows the path of least resistance.