What Is Hip Dislocation?

Developmental hip dysplasia (DDH), also known as developmental hip dislocation, is the most common hip disease in children's orthopedics, with an incidence rate of about 1 , a girl's incidence is about 6 times that of a boy, and the left side is about right 2 times on the sides, about 35% on both sides. DDH includes hip dislocation, subluxation, and acetabular dysplasia, which is more representative of all malformations of the disease than the previous name of "congenital hip dislocation".

Basic Information

nickname

Developmental hip dislocation

English name

developmental dysplasia of the hip

English alias

DDH

Visiting department

Orthopedics, pediatrics

Multiple groups

Girls

Common locations

hip joint

Common causes

Multiple births, family history, improper fetal position, wrong way of holding, etc.

Common symptoms

Lower limbs are unequal in length, have lame gait, duck step

Contagious

no

Causes of developmental hip dysplasia

Caused by multiple factors. The risk factors of the disease are: girl, first child, multiple child; those with family history; malposition of the fetus, such as breech, little amniotic fluid; adductive deformity of the foot condyles or muscular torticollis, etc .; the wrong way to sacrifice-candles package.

Clinical manifestations of developmental hip dysplasia

The clinical manifestations may vary depending on the age, degree of dislocation, unilateral or bilateral onset, etc. The main manifestations are as follows:

1. Children with unilateral dislocation may have asymmetry of hips and thighs in the early stage, but the specificity is not strong. Adduction of one hip joint. Children with bilateral dislocations have widened perineum.

2. Children with unilateral dislocation have lower limb unequal length, and children with bilateral hip dislocation during walking have lame gait and duck step.

Asymmetry of bilateral thigh pattern

Left abduction test positive

Allis sign positive

Developmental hip dysplasia

Physical examination

Early birth examinations can be positive for Ortolani sign and Barlow sign. The Ortolani sign is the abduction of the hip joint, the great trochanter lifts up, and the femoral head returns to the acetabulum when it returns to the acetabulum. Barlow sign is an irritating test, that is, the process of hip flexion and adduction touching the femoral head outward through the condyle of the acetabulum, partially or completely out of the acetabulum. A positive Ortolani sign can confirm the diagnosis of hip dislocation, while a positive Barlow sign only indicates hip instability. In the later stage, there is limited abduction of the hip joint, and the limbs are unequal in length.

2. Ultrasound

There are many methods of ultrasound examination, the most widely used is the Graf method. The Graf method measures the angles and , which represent the angle of the bony acetabulum and the angle of the cartilage portion, respectively. According to different indicators, hip joints are divided into four types, and several subtypes. Ultrasound is mainly used for infants under 6 months.

(1) Advantages High specificity and sensitivity, both greater than 90%, and few false negatives; Dislocation, subluxation, and acetabular dysplasia can be diagnosed; Dynamic observation of DDH treatment; No radiation damage .

(2) The shortcomings of the results vary greatly, and the inspectors are required to be high.

Ultrasonography

3.X check

It is more suitable for those who are more than 6 months old, and it is not recommended to perform X-ray examination for those who are less than 3 months old. Taking a hip orthophoto requires the child to be quiet, with the lower limbs shoulder width, and the toes rotated inward about 20 °. X-ray manifestations of children with DDH include an increase in the acetabular index, an interruption of the Shentong line, and a normal femoral skull center not located in the lower quadrant of the square formed by the Hilgenreiner and Perkins lines. The acetabular index decreases with age and should be within 24 ° at 2 years of age. For children younger than 8 years, the acetabular index is a reliable indicator of acetabular development. When the child is older than 5 years, the value of measuring the CE angle is great, and it is one of the most useful indicators in adult patients. When the Y-shaped cartilage is closed, the Sharp acetabular angle is also a useful indicator for measuring acetabular dysplasia.

Normal hip joint

Bilateral hip dislocation

4. Magnetic resonance imaging (MRI) examination

It is used to show the corresponding relationship between the femoral head and the acetabulum after closed reduction or open reduction. It can display both cartilage and glenoid labrum. The disadvantage is that the cost is high and the child needs sedation.

5. Computer tomography (CT) examination

It is valuable for three-dimensional reconstruction of CT in older children. The transverse scan of CT is helpful to observe whether the hip joint is reset.

Three-dimensional CT shows dislocation of left hip joint

Diagnosis of developmental hip dysplasia

Early diagnosis

Relying on physical examination and ultrasound, a positive Ortolani sign can diagnose hip dislocation, and acetabular dysplasia requires ultrasound to confirm the diagnosis.

2. Advanced diagnosis

For those with limited hip abduction, unequal leg length, lameness and duck walking, a hip joint radiograph can confirm the diagnosis.

Differential diagnosis of developmental hip dysplasia

It needs to be distinguished from multiple joint contractures, cerebral palsy, hip dislocation combined with multiple syndromes, and hip dislocation combined with suppurative hip arthritis.

Multiple joint contractures, cerebral palsy, and multiple dislocations of the hip joint are easy to identify because of some of the characteristics of the primary disease. Suppurative hip arthritis combined with dislocation of the hip joint. Ask about the history of high fever and hip dysfunction in the past. The X-ray may show signs of femoral head and acetabular damage.

Treatment of developmental hip dysplasia

The goal of DDH treatment is to obtain concentric circle reduction of the hip joint. Only in this way can provide good conditions for the development of the femoral head and acetabulum, and at the same time prevent the ischemic necrosis of the femoral head. Depending on the age of the child and the severity of the disease, the treatment is different. The earlier the treatment, the better the effect. On the contrary, as the age and the complexity of the treatment increase, the risk of complications such as avascular necrosis of the femoral head increases, and the child may develop hip degeneration and osteoarthritis in the future. .

According to different ages, the treatment methods are as follows:

1. Newborns and children under 6 months

The diagnosis is best made during the neonatal period and treated as soon as it is found. The most commonly used Pavlik jumpsuit treatment is 95% for hip joints with a positive Ortolani sign. The Pavlik jumpsuit is suitable for children with DDH within 6 months, and the failure rate of the Pavlik jumpsuit is more than 50% for those over 6 months. 3 weeks before the treatment, the condition of the Pavlik jumpsuit should be reviewed every week, and an ultrasound examination should be performed. If the hip joint is reset and stable, the review time will be extended until the ultrasound examination is normal. If the Pavlik jumpsuit does not reset after 3 weeks of treatment, the treatment fails and other treatments are needed. Complications of Pavlik jumpsuit treatment include downward dislocation of the hip joint, paralysis of the femoral and brachial plexus nerves, and ischemic necrosis of the femoral head.

Pavlik sling

2. Children from 6 months to 18 months

For children of this age, subluxation or dislocation of the hip joint should be treated by closed reduction or open reduction, and it should be treated as the first choice. For patients with acetabular dysplasia, brace treatment can be used. Closed reduction must be performed under basic anesthesia. Intraoperative arthrography shows that the reduction is satisfactory and stable, then the human is given a plaster fixation. The hip joint is required to flex at 100 to 110 °, and the abduction cannot exceed 60 °. Fixation is likely to cause ischemic necrosis of the femoral head; if the closed reduction is unsatisfactory or unstable, you need to do a hip incision and reduction, usually a simple hip incision and reduction and a human plaster cast; Hip joint reduction. Review the hip joint orthotopic radiograph before discharge, and perform CT or MRI examination if necessary to understand the reduction. Partial reexamination after discharge can be performed by ultrasound to reduce the number of X-ray examinations. Usually the plaster is fixed for about 3 months and then the brace is replaced for about 3 months. There is great potential for acetabular development after closed or open reduction, and it can last 4 to 8 years after reduction. Most children with DDH do not need to undergo acetabular or femoral surgery.

Intraoperative arthrography

Bilateral hip joint human plaster cast

3. Children from 18 months to 8 years

The acetabular development potential of children with DDH older than 18 months is very poor. Most of them need pelvic osteotomy while performing hip incision and reduction. Children with DDH under 4 years old can choose pelvic osteotomy such as Salter, Pemberton, Dega For children with high dislocations, high joint pressure after reduction, and large anteversion and neck-stem angles, it is necessary to perform shortening, derotation, and varus osteotomy of the proximal femur at the same time. Pelvic triple osteotomy can also be performed for children over 4 years old while performing the above operations, and for complex situations such as dislocation after the operation. The choice of specific surgical methods depends on the pathological changes of the hip joint and the age of the child.

Bilateral hip dislocation

Right hip incision and reduction, Pemberton pelvic osteotomy, short femoral shortening and rotational osteotomy

8 months after right operation

4. Children over 8 years

For children above 8 if bilateral dislocation is not treated, Pemberton, Dega, triple pelvic osteotomy can be performed unilaterally before Y-type cartilage closure, and Ganz pelvic osteotomy can be performed if Y-type cartilage closure. Chiari pelvic osteotomy is a kind of palliative operation, which can also achieve good treatment effect on some children.

Prognosis of developmental hip dysplasia

Children who are treated in the neonatal period have the best prognosis, and the hip joint can fully return to normal in the future. One of the most common problems in DDH treatment is ischemic necrosis of the femoral head. Once the ischemic necrosis of the femoral head occurs, the mild can recover on its own, and the severe will have different degrees of femoral head deformity. Residual deformities of varying degrees will affect the prognosis of DDH treatment. Therefore, children with DDH should be followed up to adolescent bone development for a long time, and the problems found during follow-up should be treated in time to improve the prognosis of DDH treatment.

Prevention of developmental hip dysplasia

The candle pack method of lameness and legging in children during the neonatal period is wrong and can increase the incidence of DDH by more than ten times.

The wrong "candle pack"

Popularizing the right method of tadpoles and tadpoles with free leg abduction can greatly reduce the incidence of DDH. For those who have other risk factors for DDH, physical examination and ultrasound examination should be given in the neonatal period. Early intervention if abnormalities can maximize the cure rate of DDH and reduce the disability rate.

4 steps to snoring properly

1. Fold the top corner of the blanket back, place the baby on top of the blanket, with the head above the folded corner.

2. Lift one side of the blanket against your baby's shoulder and wrap your body under the other side.

3. Fold the end of the blanket under the baby's feet and fold it towards the chest. Pay attention to leave some space under the feet to allow the baby's legs and feet to move.

4. Lift the other side of the blanket to cover the baby's body and press the tail end under the baby.