Developmental dysplasia of the hip (DDH)

At Children’s Hospital Boston, we know that the first step to treating your child’s hip dysplasia is to form a complete and accurate diagnosis. Your child’s doctor will do a physical exam—the doctor can often feel the ball popping in and out of the socket. The doctor will also take a family history (including any hip problems in your family) and may use diagnostic tests to get detailed images of your child’s hip joint.

Typical tests can include:

• ultrasound (sonogram): a painless, non-invasive imaging technique that looks inside your child's body without the use of radiation. Ultrasound is the preferred way to diagnose hip dysplasia in babies up to 6 months of age. It uses high-frequency sound waves to create pictures of organs, bones, tissues and blood vessels.

• x-ray: diagnostic radiology that shows the dense structures—including bones—inside your child’s body. After a child is 6 months of age, x-rays arethe more reliable test for her, because additional calcium coming into the head of the femur interferes with the accuracy of the ultrasound imaging. X-rays are also used to diagnose hip dysplasia in older children, adolescents and adults.