Could you explain what is developmental dysplasia of the hip?

DDH: Ddh (developmental hip dysplasia) congenital hip dysplasia is condition of abnormal development of the hip, resulting in hip joint instability and potential dislocation of proximal femur. Acetabular roof should cover the head of femur .With hip dysplasia acetabulum develops abnormally not covering femoral head. Bracing early in life helps normalize, familial tendencies, sometimes breech deliveries.