Developmental Dysplasia of the Hip: Symptoms in Children & Treatment Options by Age

What is developmental dysplasia of the hip?

Developmental dysplasia of the hip (DDH) was previously known by other terms, including congenital hip dislocation and congenital hip dysplasia. These older terms are still sometimes used, but they can be misleading. The word "congenital" implies that the condition is always present at birth, which is not always the case. In fact, DDH can develop after birth or may not be detectable until later in infancy or childhood. The term "developmental dysplasia of the hip" more accurately reflects the full spectrum of hip joint abnormalities that can occur, ranging from mild instability to complete dislocation. This terminology shift acknowledges that hip dysplasia is a dynamic condition that can evolve over time and may be influenced by both genetic and environmental factors during a child's development.

Developmental dysplasia of the hip is a condition affecting infants and young children in which abnormal development of the hip joint causes it to become unstable and predisposed to dislocation. Developmental dysplasia can be caused by a breech position of the fetus before it is born, as well as female gender, family history, and swaddling the infant.

Symptoms primarily include hip instability and a limited range of motion, as well as possible leg asymmetry or an abnormal gait.

Treatments depend on the age of the infant, and may include observation, splints or harnesses, and closed or open reductions in which the hip is put back in a proper position.

You should visit your primary care physician who will coordinate care with a muscle and bone specialist (orthopedic surgery). This condition is treated with a special harness, as well as several types of surgical procedures.

Symptoms of developmental dysplasia of the hip

Because developmental dysplasia of the hip usually affects young infants who are unable to walk or clearly communicate, the infants may not demonstrate any obvious symptoms. However, pediatricians will examine all infants for developmental dysplasia of the hip during their regular checkups from birth until about nine months of age. Some symptoms are common in all cases or can vary if the hip dysplasia is only found on one side.

Main symptoms

The main symptoms of developmental dysplasia of the hip include:

• Hip instability: Most infants with developmental dysplasia of the hip will show some symptoms of hip instability. The pediatrician tests for this using several maneuvers, which involve gently moving the infant's legs back and forth at the hip to test if the hip joint can be easily dislocated.
• Limited range of motion at the hip: This is usually apparent by two to three months, and usually limits the ability to bring the legs together.

Unilateral dysplasia

When hip dysplasia is only on one side, or unilateral, symptoms may include:

• Leg asymmetry: Infants with developmental dysplasia of the hip on only one side may have leg asymmetry, in which the leg on the affected side appears shorter than the leg on the unaffected side.
• Abnormal walking gait: Children with developmental dysplasia of the hip on only one side may exhibit an abnormal walking gait. This is because the affected leg is shorter than the leg on the unaffected side. The child may walk on their toes on the affected side, or walk with a "lurch" where their hip on the unaffected side drops when they stand on the affected side.

Causes of developmental dysplasia of the hip

The hip joint is a "ball-and-socket" joint, consisting of the head of the long bone of the leg (the femur), which is shaped like a ball, inserting into the socket of the pelvic bone, which is called the acetabulum. Normal development of the hip depends on the "ball" part of the femur and the cup-like acetabulum maintaining normal contact. If this contact is disrupted while the infant is in the uterus or during infancy, the hip joint may develop abnormally, resulting in developmental dysplasia of the hip. Specific causes of developmental dysplasia of the hip include breech position during the third trimester as well as other risk factors.

Breech position during the third trimester

Breech position during the third trimester is the greatest single risk factor for developing developmental dysplasia of the hip.

• Details: Breech position is when the fetus is positioned in the uterus feet-first instead of head-first. The risk is highest if the fetus is in frank breech, which means the hips are bent and the knees are straightened, with the toes pointing toward the head.
• Delivery options: Delivering an infant who is in breech position through Cesarean delivery (C-section) has been shown to decrease the risk of developing developmental dysplasia of the hip.

Other risk factors

Other risk factors that increase the likelihood of developmental dysplasia of the hip include:

• Female: Developmental dysplasia of the hip is at least two to three times more common in females than in males. The reason for this is unclear, although hormonal factors may be involved.
• Family history: Having a family member who had developmental dysplasia of the hip increases risk, suggesting a genetic component.
• Swaddling an infant: Using clothes or cradleboards may increase the risk of developing developmental dysplasia of the hip. This may be because tight swaddling limits hip mobility and places the legs in a position that makes them prone to dislocation.

Treatment options and prevention

Developmental dysplasia of the hip is a long-term condition that may require close follow-up and long-term treatment to manage. Hip instability is common in newborns, and hip instability in most infants will stabilize by one to two months of age without treatment and without the onset of developmental dysplasia of the hip. Therefore, treatment is usually reserved for older infants who have symptoms of developmental dysplasia of the hip. Specific treatments vary based on your child's age and are detailed below.

Infants younger than four weeks

For infants younger than four weeks of age with risk factors for developmental dysplasia of the hip or evidence of hip instability on exam, most physicians recommend close observation and follow-up rather than immediate treatment. This is because most cases of hip instability will stabilize by one to two months of age without treatment.

Infants aged four weeks to six months

For infants aged four weeks to six months with symptoms of developmental dysplasia of the hip, most physicians may recommend having the infant wear a splint or harness. These splints and harnesses keep the infant's legs in a position that reduces the risk of dislocation and promotes normal development of the hip joint. Examples of splints or harnesses include:

• Pavlik harness
• Aberdeen splint
• von Rosen splint

Infants older than six months

For infants older than six months of age with a dislocated hip that does not respond to other treatments, the physician may recommend reducing the dislocated hip (placing the bones back into their normal positions) in the operating room under general anesthesia. This can be done by:

• Closed reduction: The hip is gently manipulated without making any incisions.
• Open reduction: An incision is made to directly visualize and position the hip joint.
• A cast for recovery: Following the reduction, the hips are placed in a spica cast for six weeks to three months to maintain the hip in the proper position.

When to seek further consultation

Most pediatricians will perform screening for developmental dysplasia of the hip during the regular check-up visits in an infant's first year of life. However, it may be helpful to discuss the risk of developmental dysplasia of the hip with your child's pediatrician in the following situations:

If your infant has any risk factors for developmental dysplasia of the hip prior to birth

You should discuss this with your child's pediatrician so he or she can closely monitor for developmental dysplasia of the hip. These risks include breech position during the third trimester, female gender, or a family history of developmental dysplasia of the hip.

If your infant has any symptoms after birth

After delivery, if your infant has any symptoms of developmental dysplasia of the hip, such as leg length asymmetry or difficulty with walking, you should take him or her to see the pediatrician.