developmental dysplasia of the hip (DDH), instability of the hip joint leading to dislocation in the neonatal period. Although it may be associated with various neuromuscular disorders, such as myelodysplasia, or occur in utero, it most commonly occurs in neurologically normal infants and is multifactorial in origin. Usually there is laxity of the hip ligaments. Most affected infants are firstborn children, and 30% to 50% present in the breech position. About 90% of those affected are girls. DDH is the preferred term for babies and children with hip dysplasia because the condition can develop after birth. Formerly called congenital dislocation of the hip.
