Definition

A child born with developmental dysplasia of the hip (DDH) has a displaced or dislocated hip. The ball on the top of the femur (thigh bone) does not fit into the hip socket and is located outside of the socket. The ligaments that bind the ball and socket together stretch. The hip becomes unstable and loose.

The Hip Joint

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Causes

The exact cause of DDH is not known. But, how the baby is positioned in the womb may be a factor. Maternal hormones and genetics may also play a role.

Risk Factors

These factors increase your baby’s chance of developing DDH:

  • Gender: More common in females than males
  • Race: More common among Caucasians
  • First-born
  • Breech birth (feet first), especially females born in breech position
  • Family history of DDH
  • Swaddling the baby in a way that can dislocate the hips (more common among Native Americans and Italians)

Tell the doctor if your baby has any of these risk factors.

Symptoms

If your baby has any of these symptoms do not assume it is due to DDH. These symptoms may be caused by other conditions. Tell the doctor if your baby has any of these:

  • One leg shorter than the other
  • Poor mobility and flexibility
  • Limping, lurching, walking on toes, or other unevenness in walk (duck-like gait)
  • Uneven folds in the area of the thigh or hip

DDH more commonly affects the left hip. But sometimes both hip joints are affected. The doctor may detect the condition when the baby is born. In other cases, DDH is not diagnosed until the baby starts walking.

Diagnosis

During your baby’s first physical exam , the doctor will screen for DDH. He will gently manipulate the hip area to see if it dislocates. This would be signaled by a clunking or popping noise. Doctors can also check for DDH by placing the baby on his back and checking the height of the knees.

Other tests that may be ordered include:

  • X-ray —a test that uses radiation to take a picture of structures inside the body, especially bones
  • Ultrasound—a test that uses sound waves to examine the hips

Treatment

Talk with the doctor about the best treatment plan for your baby. Depending on your baby’s age and the severity of the condition, treatment options include:

  • For newborns: harness (called Pavlik harness) to keep hip in place, worn for 1-2 months
  • For babies aged 1-6 months:
    • Harness to reposition hip
    • Manual adjustment—the doctor moves bones into proper positions, and then places baby in a body cast
  • For babies aged six months to two years:
    • Manual adjustment
    • Hip surgery, then body cast
  • For children over two years: hip surgery, then body cast

If your baby was diagnosed with DDH at birth, the doctor may not treat the condition until the baby is older than two weeks. This is because DDH improves on its own in some cases.

The doctor will follow-up with hip exams and x-rays until your child is done growing.

Prevention

Because the exact cause is unknown, it is difficult to prevent DDH. But if you are pregnant and have a family history of DDH, tell your doctor.