Developmental Dysplasia of the Hip

Developmental dysplasia of the hip (DDH) is a problem with the formation of the hip joint. The hip is a ball and socket joint. The ball is called the femoral head and is at the top of the thighbone. The socket is called the acetabulum.

There are several types of DDH. In one type the socket is too flat, but the ball stays in the joint. In other cases the ball slips out of the joint too easily. In more severe cases the hip is dislocated (the ball is outside the socket).

DDH of the hip may be found at birth during the baby's newborn exam. It may also show up later and be discovered during a normal well baby visit with your caregiver. It can affect one or both the hips.


The exact cause is not known. Genetic factors are thought to play a role in causing DDH. It can run in the family. It is more common:


Babies with DDH usually do not have any symptoms. The folds on an infant's thighs or buttocks may appear uneven or lopsided. Older infants may have decreased outward flexibility of the hip. Older children may limp or have an unusual gait. Leg lengths may be different.


DDH may be diagnosed by a physical exam. Ultrasound of the hip may be done to confirm the diagnosis. In case of older infants and children, an x-ray of the hip may be taken. In a few cases, other kinds of imaging (such as CT or MRI) may be needed.


The treatment of DDH depends on the child's age and the response to previous treatments, if any. Babies are usually treated with a Pavlik harness. This soft device helps to hold the baby's femoral head in the socket by the use of straps that fasten about the chest and to the legs holding the legs in proper position to correct the problem. This helps form the socket properly.

Another treatment that is sometimes needed is called closed surgical reduction. This is done under general anesthesia. The surgeon moves the femoral head into the correct position by moving the thigh bone. If this does not work, an open reduction is done. This is an operation to put the femoral head in position and to correct the socket. After either type of reduction, the child's legs are held in position with a cast called a spica cast.


For babies in a Pavlik harness:

For a child in a spica cast: