[Atraumatic necrosis of the femoral head].

The incidence of atraumatic necrosis of the femoral head (ATN) has increased in recent years. The pathogenesis is complex and has a multifactorial etiology. In order to find the best possible treatment option for the often young patients, a well-coordinated evaluation, including differential diagnoses, is required. In particular, the decision whether to attempt to preserve the joint or to proceed with joint replacement is important. Knowledge of relevant classification systems is helpful in making this decision. This CME article aims to provide the necessary knowledge for the optimal treatment of ATN.