Hip Dysplasia in Babies

What is hip dysplasia in babies?

Hip dysplasia in babies, also known as developmental dysplasia of the hip (DDH), occurs when a baby’s hip socket (acetabulum) is too shallow to cover the head of the thighbone (femoral head) to fit properly. DDH ranges in severity. Some babies have a minor looseness in one or both of their hip joints. For other babies, the ball easily comes completely out of the socket.


What are the symptoms of hip dysplasia in babies?

Many babies with DDH are diagnosed during their first few months of life.

Common symptoms of DDH in infants may include:

  • The leg on the side of the affected hip may appear shorter.
  • The folds in the skin of the thigh or buttocks may appear uneven.
  • There may be a popping sensation with movement of the hip.

 

      
 In a healthy hip joint, the head the femur fits comfortably inside the hip socket. With hip dysplasia, children’s hips are prone to partially or fully dislocate. Partial dislocation is also known as subluxation.

 

What causes hip dysplasia in babies?

The exact cause is unknown, but doctors believe several factors increase a child’s risk of hip dysplasia:

  • a family history of DDH in a parent or other close relative
  • gender – girls are two to four times more likely to have the condition
  • first-born babies, whose fit in the uterus is tighter than in later babies
  • breech position during pregnancy
  • tight swaddling with legs extended

Breech position: Babies whose bottoms are below their heads while their mother is pregnant with them often end up with one or both legs extended in a partially straight position rather than folded in a fetal position. Unfortunately, this position can prevent a developing baby’s hip socket from developing properly.

Tight swaddling: Wrapping a baby’s legs in a straight position may interfere with healthy development of the joint. If you swaddle your baby, you can wrap their arms and torso snugly, but be sure to leave room for their legs to bend and move.

Angela and hip dysplasia

Angela was 5 when her parents brought her to Boston Children’s Hospital, where she was diagnosed with hip dysplasia in both hips.

How is hip dysplasia diagnosed?

Infants in the U.S. are routinely screened for hip dysplasia. During the exam, the doctor will ask about your child’s history, including their position during pregnancy. They’ll also ask if there is any history of hip problems on either parent’s side.

The doctor will do a physical exam and order diagnostic tests to get detailed images of your child’s hip. Typical tests can include:

  • Ultrasound (sonogram): Ultrasound uses high-frequency sound waves to create pictures of the femoral head (ball) and the acetabulum (socket). It is the preferred way to diagnose hip dysplasia in babies up to 6 months of age.
  • X-ray: After a child is 6 months old and bone starts to form on the head of the femur, x-rays are more reliable than ultrasounds.

How is hip dysplasia treated?

Your child’s treatment will depend on the severity of their condition. The goal of treatment is to restore normal hip function by correcting the position or structure of the joint.

Non-surgical treatment options

Observation

If your child is 3-months or younger and their hip is reasonably stable, their doctor may observe the acetabulum and femoral head as they develop. There’s a good possibility the joint will form normally on its own as your child grows.

Pavlik harness

If your child’s hip is unstable or sufficiently shallow, their doctor may recommend a Pavlik harness. The Pavlik harness is used on babies up to four months old to hold their hip in place while allowing their legs some movement. The baby usually wears the harness all day and night until their hip is stable and an ultrasound shows their hip is developing normally. Typically, this takes about eight to 12 weeks. Your child’s doctor will tell you how many hours a day your child should wear the harness. Typically, children wear the harness 24 hours a day.



 
 

While your child is wearing the harness, their doctor will frequently examine the hip and use imaging tests to monitor its development. After successful treatment, your child will need to continue to see the doctor regularly for the next few years to monitor the development and growth of their hip joint.

Typically, infants’ hips are successfully treated with the Pavlik harness. But some babies’ hips continue to be partially or completely dislocated. If this is the case, your child’s doctor may recommend another type of brace called an abduction brace. The abduction brace is made of lightweight material that supports your child’s hips and pelvis. If your child’s hip becomes stable with an abduction brace, they will wear the brace for about eight to 12 weeks. If the abduction brace does not stabilize the hip, your child may need surgery.


Surgical treatment options for babies

Closed reduction

If your child’s hip continues to be partially or completely dislocated despite the use of the Pavlik harness and bracing, they may need surgery. Under anesthesia, the doctor will insert a very fine needle in the baby’s hip and inject contrast so they can clearly view the ball and the socket. This test is called an arthrogram.

The process of setting the ball back into the socket after the arthrogram is known as a closed reduction. Once the hip is set in place, technicians will put your child in a spica cast. This cast extends from slightly below the armpits to the legs and holds the hip in place. Different casts cover differing amounts of the child’s legs, based on the condition of their hips. Children typically wear a spica cast for three to six months. The cast will be changed from time to time as your baby grows.

 

Open reduction

If a closed reduction does not work, your child’s doctor may recommend open-reduction surgery. For this, the surgeon makes an incision and repositions the hip so it can grow and function normally. The specifics of the procedure depend on your child’s condition but it may include reshaping the hip socket, redirecting the femoral head, or repairing a dislocation. After the surgery, your child will need to wear a spica cast while they heal.

Follow-up care

Any infant treated surgically for hip dysplasia must be followed periodically by an orthopedist until they have reached physical maturity. At regular visits, their orthopedic doctor will monitor their hip to ensure it develops normally as they grow. Diagnosing and treating any new abnormality early will increase the chance your child will grow up to be active free from hip pain throughout their childhood, the teen years, and adulthood.

Will treatment affect my child’s ability to walk?

Depending on their age during treatment, your child may start walking later than other kids. However, after successful treatment, children typically start walking as well as other kids. By contrast, children with untreated hip dysplasia often start walking later, and many walk with a limp.