Hip

Developmental Dysplasia of the Hip

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

Developmental dysplasia of the hip (DDH) occurs when the joint that connects the body with the leg forms abnormally. The hip is a ball and socket joint where the ball is the head of the femur (thigh bone) and the socket is the acetabulum, which is part of the pelvis.

There are two principal types of DDH:

• Unstable or Dislocated -- This is when the ball is dislocated from, or falls out of, the socket.

• Stable or Subluxated -- This is when there is no dislocation, but the socket is too small or too shallow to adequately cover or contain the ball. As a result the ball shifts around inside the socket but doesn't completely fall out.

Think of the head of the femur as an egg and the acetabulum as a spoon. In the first type of DDH, the egg falls out of the spoon. In the second type, the spoon is too shallow or too small for the egg, causing it to roll from side to side inside the spoon.

Although the cause of DDH is unknown, we do know that it is more likely in children who have relatives with DDH as well as those born via breech delivery. It also is slightly more common in firstborns, girls and Caucasians.

DDH is a disease that can strike at any time during childhood, even after it has been treated successfully. This means that a child diagnosed with DDH needs to be seen by an orthopedic surgeon until maturity. After successful treatment of DDH, your child can live a full and productive life, including full participation in sports.

The following problems are associated with DDH:

• Weakness of the hip muscles and limping
• Stiffness and loss of hip movement
• Painful arthritis

Stiffness and painful arthritis are long-term problems that may take years or even decades to set in. In turn, a child with untreated or undetected DDH generally doesn't complain, which is why some people refer to this as a silent condition and why it is important for pediatricians to screen children for DDH.

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 8, 2007