[Embryology of the human hip with special reference to the development of the labra]

For the clinician the knowledge of the intrauterine development of the human hip is of great importance particularly for an understanding of the pathogenesis of congenital hip displacement. Observations based on serial sections of fetal hips from our collection showed that the acetabular roof is generally well developed. The posterior wall, on the other hand, consists mostly of the fibrous labrum and little coverage is provided by cartilage. Since the fetal hip is in a position of flexion, a pressure exerted on the knee will be transmitted to the posterior wall of the acetabulum and not to the acetabular roof. Any additional adduction, often found in utero, will further decrease the coverage. Both, the relative weak posterior structures and the position of adduction, may explain the posterior subluxation observed in one of our specimens.