Hip Dysplasia in Infants

Hip Dysplasia is a very deforming condition that affects many infants around the world. Read on to know all about Hip Dysplasia in Infants including its causes, symptoms, diagnosis and treatment.

What is Hip Dysplasia?

It is a condition characterized by a hip joint deformity found to be present at birth. The spectrum of this disease is wide in nature and ranges from moderate instability of the hip to long-time hip dislocation.

Incidence of Hip Dysplasia in Infants

The condition is found to occur in one out of every thousand live births. The prevalence of hip instability is higher in just-born infants rather than those who are about four weeks old. It affects one in every 3000 boys and one out of every 600 girls.

Hip Dysplasia in Infants Symptoms

Some of the main signs and symptoms of Hip Dysplasia (HD) in infants are:

Hip click

This is characterized by a pop or snap sound in normal hips that occur from developing ligaments located in the hip joint and the surrounding regions.

Limited range of motion

Affected infants often suffer from limited flexibility or mobility in the impacted side of the hips. They find it difficult to spread hips completely. Parents often experience difficulties in making their affected infants wear diapers.

Pain

Infants and young kids with HD do not usually suffer from painful symptoms. Pain generally arises in HD patients during adolescence and early stages of adulthood.

In HD patients, the leg on the side of the dislocated hip may appear shorter or turn outward. The hip may be partially or totally dislocated, which means the femur ball may slip partially or completely out of the socket of the hip. Older patients generally walk with a distinct waddling gait, due to one hip being lower than the other. They may walk on tiptoe or with a limp.

In some cases, the skin folds of the buttocks or the thigh can appear uneven and the space between the legs can appear wider than usual.

What Causes Hip Dysplasia in Infants?

It is not known what exactly causes this problem in infants. It is, however, widely believed to be developmental in nature. This is due to the fact that HD is known to occur around or after the time of birth or even during the stage of childhood. This is precisely the reason why the syndrome is also known as Development Dysplasia of the Hip (DDH) or Congenital Hip Dysplasia (CHD).

Some of the main causes of Hip Dysplasia (HD) are believed to include factors like:

Family history

Genetics is supposed to play a role in the development of this condition, though not a direct one. Around one-third of all babies with HD are found to have a blood relative suffering from this disorder. A child of an HD parent has 12% risk of getting this disease. One out of 10 newborns with an HD parent or sibling can suffer from this problem.

Congenital disorders

Babies with congenital diseases, such as Spina Bifida and Cerebral Palsy, are seen to be vulnerable to this disease.

Hormonal changes

In some cases, hormonal changes occurring within a pregnant woman results in the relaxation of the ligaments of her body. The ligaments become easily stretchable to allow babies to pass easily through the birth canal. This is a natural phenomenon that can often cause unusual loosening of the ligaments of a baby, while it is still in the womb. Certain infants are highly sensitive to hormonal changes than others, which increases their likelihood of getting this condition.

Positioning in the womb

The positioning of the fetus inside the womb can also be responsible for this condition. Generally, babies lying in a normal position within the womb suffer from more stress on the left hip than on the right one. It is due to this reason that the left hip is thought to be affected more. Babies in a breech position are more susceptible to hip instability than those in a normal womb position. Excess pressure on the hip joints stretches the ligaments, thereby increasing the risk of HD.

Manner of cradling

Some cultures, which cradle infants with their hips extended on a papoose board or cradleboard, have high incidence of hip dysplasia in children. Regions that have people holding infants with their hips apart are found to have extremely low rates of this condition. Due to this reason, one should avoid swaddling infants with their hips extended for at least a few months after birth. The bones of the hip joint of an infant are quite softer than those in adults.

Hip Dysplasia in Infants Diagnosis

The condition is sometimes observed at birth. When infants are born, newborn specialists or pediatricians often screen them in the hospital to detect this hip condition. However, the disorder may not be diagnosed until later evaluations. A clinical examination by an experienced physician often helps diagnose HD. During tests, physicians may obtain a complete history of the infant, both before and after its birth.

Diagnostic procedures may include:

• X-ray examination
• Ultrasound (Also known as Sonography)
• Computed Tomography Scan (CT scan)
• Magnetic resonance imaging (MRI scan)

In some cases, however, DDH may not be diagnosed until the child has become two or three years of age.

Hip Dysplasia in Infants Treatment

Treatment for this condition aims at replacing the femoral head into the acetabulum (hip socket). Pressure is incessantly exerted over the hip socket to enlarge it. This allows normal development of the hip.

Specific treatment for the condition is determined by a physician on the basis of several factors, such as:

• Gestational age of the infant
• Overall health of the baby
• Medical history of the infant
• Severity of the condition
• Preference of parents
• Tolerance of the baby to particular medications, therapies or procedures

For patients affected with DDH, treatment options may vary and include procedures like:

Casting

In this process, the affected hip joint may be put into a cast to avoid stress on the ligaments. Casting may be considered if there is partial or complete dislocation of the hip.

Pavlik harness placement

The Pavlik harness is a non-surgical positioning device that is used on babies who are up to 6 months old. The device helps hold the hip in position, while allowing a little space to the legs for movement. The harness is fixed in place by an experienced physician. Generally, babies need to wear it at all times for a minimum period of six to eight weeks after birth. Following this, patients way wear it for 12 hours every day for six weeks. The treatment should be followed by an X-ray or an ultrasound examination to detect any improvement in hip placement. Pavlik harness is generally successful in curing DDH though the affected hip may continue to be completely or partially dislocated even after use of the device.

Surgery

In some cases, a surgical operation may be needed to manually reposition the hip back into place. The process is also referred to as a “Closed Reduction” and is used only if other procedures fail to yield successful results, or if DDH is detected at anytime between 6 months and 2 years after the birth of an infant. In children over 2 years of age, an “open surgery” may be needed to realign the hip. If this turns out to be successful, a special cast known as a “Spica Cast” is placed on the baby to keep the hip in position. The cast needs to be worn for around three to six months. The cast is occasionally changed to allow space for the bone growth. Taking it off at times ensures that the cast remains rigid, as it may weaken due to daily wear. The cast is allowed to remain on the hip until its placement gets normal. After casting, physical therapy exercises and/or a special brace may be required to ensure strengthening of the muscles in the legs and around the hip region.

Prognosis of Hip Dysplasia in Infants

In most patients, the condition is found to have a good outcome with proper treatment. It is necessary to correct congenital hip dysplasia cases as soon as possible after birth. Unless this is done, the growing femur may suffer deformities due to unusual stress. Children affected with such malformation may suffer from walking difficulties and painful symptoms all through their life. The abnormal positioning of the hip forces the acetabulum to shift to another spot and make room for the displaced femur. Patients with untreated DDH have a characteristic limp or a waddling gait.

Prevention of Hip Dysplasia in Infants

The condition may be prevented with proper prenatal care that helps evaluate the fetal position within the womb. This may help in preparing for possible birth of the infant from a breech presentation (breech birth) related with hip problems. Avoiding prolonged and undue hip adduction in infants may help prevent strain on the hip joints. Early diagnosis is considered to be extremely important in preventing Congenital Hip Dysplasia.

Complications of Hip Dysplasia in Infants

In older children, untreated DDH may result in problems in stability. The nerves serving the femur may also suffer from trauma (injury). If successfully treated, however, the condition does not cause any hip problems in future in most infants. Some patients may, however, suffer from arthritis in their later years in the impacted joint. In an older child, untreated DDH may cause stability problems as well as trauma to nerves that serve the femur. In adult years, it may be not be possible to avoid a total hip surgery.

If your child is showing a waddling gait and you suspect a Hip Dysplasia, immediately seek medical attention. As aforesaid, timely diagnosis is the key to preventing this condition from worsening. The quicker it is treated, the lesser will be the physical problems for your child.

References:

http://emedicine.medscape.com/article/1248135-overview

http://www.lpch.org/DiseaseHealthInfo/HealthLibrary/orthopaedics/ddh.html

http://arthritis-symptom.com/h-l/hip-dysplasia.htm

http://4kidsortho.com/html/hip_dysplasia.html

http://www.hipdysplasia.org/Developmental-Dysplasia-Of-The-Hip/Causes/default.aspx