[Femoral torsional deformities]

First, we describe the physiological development of the torsion of the femoral neck, starting from about an angle of 35 degrees at the time of birth up to an angle of a mean value of about 15 degrees at the end of bone growth. Furthermore, we explain diagnostic procedures (clinical examination, X-ray, tomography) according to their clinical relevance. The differences from the normal range are discussed in their pathogenetic context with the clinical symptoms characteristic for the hip and knee joint. The most relevant aspect of the pathological torsion of the femoral neck is a decreased antetorsion angle, while an increased antetorsion angle was overestimated in the past.