Developmental Dysplasia of the Hip in Children

What is developmental dysplasia of the hip in children?

Developmental dysplasia of the hip (DDH) is a health problem of the hip joint. It’s when the joint hasn’t formed normally, so it doesn’t work as it should. DDH is present at birth. It is more common in girls than boys. 

In a normal hip joint, the top (head) of the thighbone (femur) fits snugly into the hip socket. In a child with DDH, the hip socket is shallow. As a result, the head of the femur may slip in and out. It may dislocate. This means it moves partly or completely out of the hip socket.

What causes DDH in a child?

A combination of things may lead to DDH. It may be partly genetic. DDH tends to run in families. It may also be partly environmental, such as:

  • The baby’s response to the mother’s hormones during pregnancy
  • A tight uterus that makes it hard for the fetus to move around
  • A breech delivery, when the baby is born bottom-first instead of headfirst

Which children are at risk for DDH?

First-born babies are at higher risk because the uterus is small and there is limited room for the baby to move. That may affect how the hip develops. Other risk factors are:

  • Family history of DDH, or very flexible ligaments
  • Position of the baby in the uterus, especially the breech position
  • Other orthopedic problems, such as clubfoot
  • Female sex. DDH is more common in girls than boys.

What are the symptoms of DDH in a child?

The following are the most common symptoms of DDH. Symptoms can occur a bit differently in each baby. They can include:

  • The leg may appear shorter on the side of the dislocated hip
  • The leg on the side of the dislocated hip may turn outward
  • The folds in the skin of the thigh or buttocks may appear uneven
  • The space between the legs may look wider than normal

The symptoms of DDH may seem like other health problems of the hip. Make sure your baby sees his or her healthcare provider for a diagnosis.

How is DDH diagnosed in a child?

DDH is sometimes noted at birth. A healthcare provider screens newborn babies in the hospital for this hip problem before they go home. But DDH may not be discovered until later checkups.

Your baby’s healthcare provider makes the diagnosis of DDH with a physical exam. During the exam, he or she asks about your baby’s birth history and whether other family members have DDH.

Your baby may also need these tests:

  • X-rays. This test makes images of internal tissues, bones, and organs.
  • Ultrasound (sonography). This test uses high-frequency sound waves and a computer to make images of blood vessels, tissues, and organs. It is used to view internal organs as they function and to assess blood flow through various vessels.