Developmental dysplasia of the hip

DDH is a condition in which the relationship between the hip socket and femoral head is abnormal. It may be present at birth or occur in an infant or child's development. It occurs once or twice in every 1,000 live births. The hip joint is created as a ball and socket joint. In DDH, the hip socket may be shallow, letting the "ball" of the long leg bone, also known as the femoral head, slip in and out of the socket. The "ball" may move partially or completely out of the hip socket.

The greatest incidence of DDH occurs in first-born females with a history of a close relative with the condition.

Risk factors

Below are some of the common risk factors associated with DDH:

• Female gender
• First born infants thought due to the mother's uterus being smaller, therefore, less room to move
• Position of the baby in uterus such as breech presentation
• Family history of DDH
• Associations with other orthopedic conditions such as clubfoot deformity, congenital conditions, and other syndromes

Symptoms

The following are the most common symptoms of DDH. However, each baby may experience symptoms differently. Symptoms may include:

• The leg may appear shorter on the side of the dislocated hip
• The leg on the side of the dislocated hip may turn outward
• The folds in the skin of the thigh or buttocks may appear uneven

Diagnosis

Developmental dysplasia of the hip is sometimes noted at birth. The pediatrician or newborn specialist screens newborn babies in the hospital for this hip problem before they go home. However, DDH may not develop until later in infancy or childhood so your pediatrician may diagnose it at a later well child visit. Your baby's physician makes the possible diagnosis of developmental dysplasia of the hip with a clinical examination. They may then order certain diagnostic tests such as an ultrasound of the hips to confirm the diagnosis and/or refer you on to a pediatric orthopedic specialist.

Treatment:

Specific treatment for DDH will be determined by your baby's physician and orthopedic specialist based on:

• Your baby's age, overall health, and medical history
• The extent of the condition
• Expectations for the course of the condition
• Your opinion or preference

The goal of treatment is to maintain the femoral head into the socket of the hip so that the hip can develop normally.

Treatment options vary for babies and may include:

• Placement of a Pavlik harness - The Pavlik harness is used on babies up to 6 months of age to hold the hip in place, while allowing the legs to move a little. The harness is put on by your baby's physician and is usually worn full time for at least six weeks, then part-time (12 hours per day) for six weeks. Your baby is seen frequently during this time so that the harness may be checked for proper fit and to examine the hip. At the end of this treatment, x-rays (or an ultrasound) are used to check hip placement. The hip may be successfully treated with the Pavlik harness, but sometimes, it may continue to be partially or completely dislocated.
• Casting and surgery - If the hip continues to be partially or completely dislocated, often casting or surgery may be required to help relocate the hip. If surgery is done, a special cast called a spica cast is put on the baby to hold the hip in place. The spica cast is worn for approximately three to six months. The cast is changed from time to time to accommodate the growth.

What is a short leg hip spica cast?

A short leg hip spica cast is applied from the chest to the thighs or knees. This type of cast is used to hold the hip in place after surgery to allow healing.

Cast care instructions:

• Keep the cast clean and dry
• Check for cracks or breaks in the cast
• Rough edges can be padded to protect the skin from scratches
• Do not scratch the skin under the cast by inserting objects inside the cast
• Use a hairdryer placed on a cool setting to blow air under the cast and cool down the hot, itchy skin. Never blow warm or hot air into the cast
• Do not put powders or lotion inside the cast
• Cover the cast during feedings to prevent spills from entering the cast
• Prevent small toys or objects from being put inside the cast
• Elevate the cast above the level of the heart to decrease swelling
• Do not use the abduction bar on the cast to lift or carry the baby

When to call your baby's physician

Contact your baby's physician or healthcare provider if your baby develops one or more of the following symptoms:

• Fever
• Increased pain
• Increased swelling above or below the cast
• Drainage or foul odor from the cast
• Cool or cold toes