Hip dysplasia. Causes and symptoms

• General information about hip dysplasia
• What is hip dysplasia?
• Causes of hip dysplasia
• Symptoms of hip dysplasia
• Examination in hip dysplasia
• Treatment of hip dysplasia
• Postoperative recovery
• Possible treatment complications
• Hip dysplasia. Conclusions

General information about hip dysplasia

The hip joint is a ball-and-socket joint. In a normal hip, the upper part of the femur, the femoral head, sits firmly in the acetabular cavity, which is part of the hip bone. In infants and children with hip dysplasia, the hip joint has not formed normally. The femoral head is loose in the joint and can be easily dislocated. Although hip dysplasia is most often present at birth, it can also develop in the child's first year of life. Recent research shows that babies whose legs are swaddled tightly, with the knees pressed together and the legs straight, have a notably higher risk of developing dysplasia after birth. Since swaddling is becoming increasingly popular nowadays, it is important for parents to learn to do it correctly. Improper swaddling can increase the risk of hip dysplasia.

What is hip dysplasia?

In all cases of hip dysplasia, the joint between the acetabulum and the femoral head is unstable and slips. Sometimes, the ligaments that help maintain and stabilize the joint are stretched, and the degree of hip weakness or instability increases. This degree of instability differs for each individual child. Hip dysplasia is divided into 3 categories, depending on the relationship between the acetabulum and the femoral head:

• Dislocated - In the most severe cases of hip dysplasia, the head of the femur is completely outside its socket (the acetabulum).
• Dislocatable - In these cases, the head of the femur is inside the acetabulum, but can easily be pushed out of the socket during a physical examination.
• Subluxated - In mild cases of hip dysplasia, the head of the femur is simply partly out of the acetabulum. During a physical examination, the bone can be moved back inside the acetabulum, but will not dislocate.

In the United States, approximately 1 to 2 children per 1000 are born with hip dysplasia. Pediatricians detect dysplasia at the newborn's first examination and at each baby checkup thereafter.

Causes of hip dysplasia

Hip dysplasia tends to have a genetic component. Studies show that it usually affects the left hip and is predominant in:

• Girls
• Firstborn children
• Children born in breech position
• Family history of hip dysplasia (parents or siblings)
• Oligohydramnios (low levels of amniotic fluid)

Symptoms of hip dysplasia

It is important to know that some children born with hip dysplasia do NOT show external signs. Contact your pediatrician if your child has:

• Legs of different lengths
• Uneven thigh folds
• Reduced mobility or flexibility of the limbs on one side
• Limping, walking on tiptoes, or a waddling gait 

Examination in hip dysplasia

In addition to visual clues, your doctor will perform a careful physical examination to check for the possible presence of hip dysplasia. Signs such as a "clicking" sensation or a specific sound, along with specific maneuvers to determine whether the hip can be dislocated and/or put back into the correct position, are part of the medical examination.

Newborns identified as being at higher risk for hip dysplasia are often tested using ultrasound. 

The American Academy of Pediatrics now recommends screening for dysplasia through ultrasound examination for all female infants.

For infants and older children, a hip X-ray is a good method for providing detailed images of the hip joint.

Treatment of hip dysplasia

When hip dysplasia is detected at birth, it can usually be corrected with the help of a harness or brace. If the hip is not dislocated at birth, or if no clinical and imaging check has been performed, the condition may not be noticed until the child begins to walk. At this point, treatment is more complicated and the results are less predictable.

Non-surgical treatment

Treatment methods differ depending on the child's age.

In newborns:

The baby is placed in a soft positioning device, called the Pavlik harness, for 1 to 2 months to keep the bone in the joint. This type of harness is specially designed to keep the hip in the correct position, while allowing free movement of the legs and easy diaper care. The Pavlik harness helps tighten the ligaments around the hip joint and promotes normal formation of the acetabulum.

Parents play an essential role in ensuring the effectiveness of the harness. Your doctor and the medical care team will teach you how to safely perform the baby's daily care, such as changing diapers, bathing, feeding and dressing.

Between 1 and 6 months:

In this interval, treatment is not very different from that for a newborn. The child's thigh is repositioned using a harness or a similar device. This method is usually successful, even with hips that were initially dislocated. The time the child must spend with the harness attached varies. It usually must be worn for at least 6 weeks, a minimum of 8 hours a day, and then the time is reduced by half for another 6 weeks. If the hip does not stay in position using a harness, the doctor may try a firmer abduction brace, which will keep the child's legs in the correct position. 

In some cases, a special closed reduction procedure is necessary. The doctor will move the femoral head into the correct position, then apply a cast (spica cast) to hold the bones in place and stabilize the joint. This procedure is done while the child is under anesthesia.

From 6 months to 2 years

For children between 6 months and 2 years old, the treatment is closed reduction and a cast. The other methods (harnesses) are not truly successful methods because in this age range the child becomes increasingly active, so the only method remaining is the cast.

Surgical treatment

If a closed reduction procedure with a cast fails to place the femoral head in the correct position, open surgery is necessary. In this procedure, an incision is made at the hip that allows the surgeon to clearly see the bones and soft tissues of the hip joint. For precision, X-rays are taken during the operation to confirm the correct placement of the bones in the joint. Also, after the operation, the child will be placed in a cast to protect and stabilize the joint. Unfortunately, in children over 2 years old, joint weakness usually worsens as the child becomes more active, and open surgery is usually necessary to align the hip.

Postoperative recovery

In many children with hip dysplasia, a cast and/or a harness is necessary to keep the femoral head in the correct position in the joint during healing. X-rays and periodic checkups are necessary after surgical treatment until the child's bone development is complete.

Possible treatment complications

Children treated with a cast may have a delay in walking. However, once it is removed, walking development continues normally. The Pavlik harness and other positioning devices can cause skin irritation around the straps and can create a difference in leg length. Growth disturbances of the upper thigh are rare, but can occur due to a disruption of the blood supply in the thigh's growth area.

Hip dysplasia. Conclusions

If diagnosed early and treated successfully, children are able to develop a normal hip joint and should not have any limitation in movement. Left untreated, hip dysplasia can lead to pain and osteoarthritis in early adulthood. It can produce a difference in leg length or a decrease in agility. Even with appropriate treatment, hip deformity and osteoarthritis can develop later in life. This is especially true when treatment begins after age 2.

Centrokinetic is the place where you will find answers and clear solutions for your mobility problems. The clinic dedicated to bone and joint conditions is divided into the following specialized departments:

• Orthopedics, a department made up of a highly experienced team of orthopedic surgeons, led by Dr. Andrei Ioan Bogdan, senior physician in orthopedics-traumatology, with surgical activity at  the Medlife Orthopedic Hospital, specialized in sports traumatology and in ankle and foot surgery.
• Pediatric orthopedics, where children's sports injuries are treated (ligament and meniscus injuries), spinal deformities (scoliosis, kyphosis, hyperlordosis) and foot conditions (hallux valgus, hallux rigidus, clubfoot, flat valgus foot, cavus foot).
• Neurology,  which has a state-of-the-art department, where consultations, electroencephalograms (EEG) and electromyograms (EMG) are performed. 
• Medical rehabilitation for adults and children, a department specialized in the recovery of performance athletes, in spinal conditions, and in the recovery of children with neurological and traumatic conditions. Our experience is extremely rich, having treated over 5000 performance athletes.
• Medical imaging, the clinic being equipped with ultrasound and MRI, high-performance devices dedicated to musculoskeletal conditions, and complemented by an experienced team of radiologists: Dr. Sorin Ghiea and Dr. Cosmin Pantu, specialized in musculoskeletal imaging.

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