[The importance of the long pelvis in clinical practice and medical education (author's transl)].

The importance of the long pelvis with lumbo-sacral assimilation in obstetrics is evaluated. 111 x-rays of the pelvis in cases with abnormal deliveries were evaluated and compared to the clinical data. The incidence of the long pelvis was not increased in the total group, nor in the 100 cases with abnormal deliveries. A long pelvis was present in 30.2% of the 43 breech presentations. In 4 cases with a funnel pelvis vaginal delivery occurred without difficulty. In 42 posterior vertex presentation the long pelvis appears to have a pathogenetic importance regarding the primary posterior position. The further course of the delivery was not influenced by the long pelvis. In 7 cases of low transverse arrest, 4 had a long pelvis but only 1 had a funnel pelvis to explain this abnormal position. In summary, the long pelvis even in its most severe form, the funnel pelvis, does not block the adaptation processes in the lesser pelvis. The changes in the pelvic inlet due to the lumbo-sacral assimilation have an etiologic importance on the initial presentation at the inlet such as breech presentation, military vertex presentation, brow presentation, or Roederers anomaly. However, no prognostic value for the mechanism of the delivery can be derived from the initial presentation. The delivery dose not depend on the long pelvis but on the malpresentation when delivery becomes necessary.