[Functional anatomy of the upper ankle joint].

The ankle joint is regarded as a hinged joint with a range of motion of about 60 degrees. The shape of the trochlea tali varies, so the axis of rotation and the compensative movements of the fibula do. The ligamentous stabilizers of the medial side are thicker than the lateral ones. At the other hand, the lateral malleolus is more voluminous than the medial one. The lig. fibulotalare ant. is a reinforcement of the joint capsule, the lig. fibulocalcaneare has no connection to the jointcapsule, the lig. fibulotalare post. is partially running through the joint. In neutral- and plantarflexed position, the lig. fibulocalcaneare forms a groove which takes up the tendon sheat of the peroneal tendson. In dorsalextended position the tendons are pushed laterally by the tense ligament. This mechanism supports the peroneal tendon luxation in dorsal extension.