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Developmental dysplasia of the hip

  • Definition

    Developmental dysplasia of the hip (DDH) is a dislocation of the hip joint that is present at birth. The condition is found in babies or young children.

    Alternative Names

    Developmental dislocation of the hip joint; Developmental hip dysplasia; DDH; Congenital dysplasia of the hip; Congenital dislocation of the hip; CDH; Pavlik harness

    Causes, incidence, and risk factors

    The hip is a ball and socket joint. The ball, called the femoral head, forms the top part of the thigh bone (femur) and the socket (acetabulum) forms in the pelvic bone.

    In some newborns, the socket is too shallow and the ball (thigh bone) may slip out of the socket, either part of the way or completely. One or both hips may be involved.

    The cause is unknown. Low levels of amniotic fluid in the womb during pregnancy can increase a baby's risk of DDH. Other risk factors include:

    • Being the first child
    • Being female
    • Breech position during pregnancy, in which the baby's bottom is down
    • Family history of the disorder

    DDH occurs in about 1 out of 1,000 births.