[Lateral instability of the upper ankle joint].

Because of their frequency, ankle sprains are of major clinical and economic importance. The simple sprain with uneventful healing has to be distinguished from the potentially complicated sprain which is at risk of transition to chronic ankle instability. Conservative treatment is indicated for the acute, simple ankle sprain without accompanying injuries and also in cases of chronic instability. If conservative treatment fails, good results can be achieved by anatomic ligament reconstruction of the lateral ankle ligaments. Arthroscopic techniques offer the advantage of joint inspection and addressing intra-articular pathologies in combination with ligament repair. Accompanying pathologies must be adequately addressed during ligament repair to avoid persistent ankle discomfort. If syndesmotic insufficiency and tibiofibular instability are suspected, the objective should be early diagnosis with MRI and surgical repair.