Congenital hip dislocation is mainly due to developmental defects in the acetabulum, proximal femur and joint capsule, resulting in instability of the joint until it develops into dislocation of the hip joint. If the normal relationship between the joint components is corrected and restored, the joint will develop normally with growth, so some experts also call it congenital hip dysplasia. The incidence of congenital hip dysplasia in infants ranges from 1% to 3.9%. The incidence varies greatly by race and region. In China, the average incidence rate of hip dysplasia in newborns in six major cities is 3.9%. It is more common in females than males, about 6:1. It is more common on the left side than on the right side, and less common in bilateral cases.
The etiology of the disease: multifactorial effects. Genetic factors, about 20% of affected children have family history; acetabular dysplasia and laxity of joint ligaments; abnormal fetal position in the womb and abnormal mechanical pressure, which affects the development of hip joint, can cause developmental hip dislocation.
What are the manifestations of congenital hip dislocation? How should it be diagnosed?
I. Pre-standing
Clinical symptoms are often not obvious in newborns and infants, and often cannot attract parents’ attention. If the following signs are found, the possibility of developmental hip dislocation should be considered.
1. Asymmetrical skin folds on the inner thighs of both sides, with increased skin fold deepening on the affected side.
2. Widening of the perineum of the affected child, which is more obvious in bilateral dislocation.
3. The hip joint on the affected side has less movement and is restricted. The pedaling force is weaker than that of the healthy side. It is often in the flexed position and cannot be straightened.
4.The affected limb is shortened.
5.There is a popping sound or popping sensation when pulling the lower limb on the affected side.
Dislocation period
The child usually starts walking later than normal children. In unilateral dislocation, the child is limping. In the case of bilateral dislocation, the pelvis is tilted forward when standing, the hips are shrugged backward, the lumbar foreshortening is especially obvious, and the child walks with a “duck gait”. When the child is supine and the hip and knee are flexed at 90°, the knee joints are not in the same plane bilaterally. When pushing and pulling the femur on the affected side, the femoral head can move up and down, like a pump. The nature and degree of dislocation can be clarified by radiography.
How should congenital hip dislocation be treated?
The treatment of congenital hip dislocation should emphasize early diagnosis and the best treatment effect in infancy, and the older the age, the worse the effect. It is generally believed that even if the treatment is very successful after 2 to 3 years old, hip pain will occur after 35 years old, so early diagnosis and treatment are important measures to obtain a cure. If a typical congenital hip dislocation is treated early and correctly, it is very likely to develop into a normal hip joint under normal functional stimulation. Those who are treated within 3 years of age have a high cure rate. With the growth of age, the bony components of the femoral head and acetabulum increase, plasticity decreases, and pathological changes aggravate, so it is difficult to achieve normal function despite correct treatment.
1. Treatment for children within 1 year of age: the best time for non-surgical treatment. Use simple supports to ensure the repositioning of the femoral head, such as diapers, dressing gowns, etc. If the child is older than 6 months, apply external fixation brace to keep both hips flexed and out of the booth for about 3 months after manual repositioning.
2, 1 to 3 years old children’s treatment: still based on non-surgical treatment methods. In order to make the closed reset successful, continuous skin traction on both lower limbs should be used for 2 to 3 weeks before the reset to make the femoral head descend and relax the muscles and ligaments around the hip joint. General anesthesia is used during the reset, and after the reset, a frog-shaped cast is fixed and replaced every 3 months for 6 to 9 months. After release of fixation, functional exercise should be strengthened.
3, treatment of children over 3 years old: due to the older age, the secondary lesions of congenital hip dislocation are aggravated, and the manual closed reset can hardly be completed, so the main treatment is surgery, which is characterized by fully loosening the contracted muscles and ligament tissues around the hip joint, and correcting the bony deformity of the acetabulum and upper femur on the basis of incisional reset.
The methods are.
(1) Salter pelvic osteotomy: the principle is to change the direction of the acetabulum so that the acetabulum is displaced forward and downward to better cover the femoral head, and this procedure is the preferred surgical method for children aged 3 to 6 years.
(2) Internal pelvic displacement osteotomy: Chiari osteotomy, mainly for adolescent patients.
(3) Acetabularplasty: also known as acetabular topography, the main purpose is to increase the coverage area of the acetabulum on the femoral head and restore the normal curved structure of the upper part of the medullary socket, which is suitable for older children with hip dislocation, acetabular dysplasia and acetabular index greater than 45°.