Congenital hip dislocation

Introduction to congenital dislocation of the hip Congenital dislocation of the hip is one of the most common congenital malformations in children. Later dislocation is more common. It is already present at birth. The lesions involve the acetabulum, musculoskeletal, joint capsule, ligament and nearby muscles, causing joint relaxation. Subluxation or dislocation. Sometimes there may be other malformations, such as congenital torticollis, hydrocephalus, meningocele, congenital dislocation or contracture of other joints. basic knowledge The proportion of illness: 0.005% Susceptible people: young children Mode of infection: non-infectious Complications: ischemic necrosis sciatic nerve injury

Congenital dislocation of the hip

The etiology of congenital dislocation of the hip has not yet been fully clarified. Of course, multiple dislocations with hip dislocation should be congenital malformations. In general, most scholars believe that the cause is not single in recent years. Many factors will participate in this disease.

Genetic factors (25%):

There is no undeniable fact that this disease has a clear family history, especially in twins. The incidence of this family of patients can be as high as 20 to 30%, and more common in sisters, the same The disease can occur in the sisters of the three types of hip dislocation subluxation and dysplasia, if detailed, early examination and X-ray diagnosis, in addition to the first category, the latter two categories can often be missed and reach 7, At the age of 8, the hips are completely normal.

Ligament relaxation factor (20%):

In recent years, more and more reports have proved that the relaxation of joint ligament is an important factor. In animal experiments, Smith has a high percentage of hip dislocation after the removal of the joint capsule and round ligament of the dog. Clinically, Andren pointed out that the X-ray film The separation of the pubic symphysis is twice that of normal infants in the case of hip dislocation. He believes that this is the mother's need for a large amount of endocrine in the production process to relax the ligament. Excessive endocrine changes are an important factor in hip dislocation. Andren, Borglin found that urinary estrone (Estrone) estradiol 17 (Estradil) was changed within 3 days of neonatal hip dislocation, compared with normal infants, but Thieme used 16 sick infants compared with 19 normal infants. When measured monthly, there was no difference after statistical processing. Therefore, the theory of endocrine changes causing ligament relaxation is still not established.

Position and mechanical factors (19%):

In the case of hip dislocation, breech production has been reported as high as 16 to 30%, and normal breech production is only 3%. Wikinson (1963) fixed the hip joint of the child to flexion, external rotation, knee extension, and given Estrogen and progesterone can cause dislocation of the hip joint.

Post-natal position is also considered to be a factor in the disease, such as the high incidence of Indian and American Indians due to the use of sputum in infants.

Congenital dislocation of the hip

The disease is congenital disease, there is no effective preventive measures, although the time between non-surgical treatment and surgical treatment is not much different, but the effect on children is very different, so the early detection of congenital dislocation of the hip, Early diagnosis and early treatment are very important and must be paid enough attention by parents and doctors, especially in some rural areas. Due to some old ideas, it is considered that children are too dangerous to perform surgery or they can be treated later if they are not dead. It has caused a disease that could have been cured for several hundred dollars, and it cost thousands of yuan or tens of thousands of dollars to the end of the disease, which brings a great burden to the patient's family and increases the risk of child disability.

Congenital hip dislocation complications Complications ischemic necrosis sciatic nerve injury

Congenital dislocation of the hip, most of the complications after treatment are rude and rude, traction is not enough, the indications for surgery are not mastered, and the factors that hinder the reduction and improper fixation are not clarified. Most of them can be avoided. Common complications are:

(1) Re-dislocation: Often due to hindering the reduction factor, the X-ray is illusory, the gypsum is not careless, the anteversion angle is too large, or the acetabulum is poorly developed, so even after the reduction, it is easier to dislocate.

(B) avascular necrosis of the femoral head: This type of complication is mainly due to rude manipulation or excessive surgical trauma, damage to the blood supply of the femoral head; strong abduction during fixation; insufficient traction or adductor muscle before reduction, The iliopsoas muscles were not loosened, and the femoral head was over-stressed after resetting and some reasons were unknown.

(C) hip osteoarthritis: is a late complication, usually after surgery in older children, it is often difficult to avoid some types of complications after adulthood.

(4) Separation of the femoral condyle: the fracture of the upper part of the femur, the injury of the sciatic nerve, etc. These are caused by insufficient traction, use of violence during the reduction or too shallow anesthesia, and can generally be avoided.

Congenital dislocation of the hip Symptoms Common symptoms Joint relaxation gluteal muscle atrophy Hip joint pain Hip joint effusion

(1) Limited joint activity In children with congenital dislocation of the hip, it is usually characterized by painlessness and unrestricted joint activity. In the baby and neonatal period, however, there is a temporary joint dysfunction with a certain fixed posture. The typical symptoms are that the child's limbs are flexed and do not dare to straighten, the activity is worse than the healthy side, and the force is weak. When the lower limbs are pulled, they can be straightened, but after the loose hand, they are flexed. A few infants have external rotations, and the outer booth or outer booth. The lower limbs are in a cross position, and even the hip joint is completely stiff. A few children have crying when pulling the lower limbs.

(B) limb shortening unilateral hip dislocation common limb shortening.

(3) Other common symptoms include asymmetry of the labia majora, increased wrinkles in the buttocks, inner thighs or armpits, deepening or asymmetry, widening the perineum, and sometimes squeaking or bouncing when the affected limb is pulled sense.

Congenital dislocation of the hip

Mainly rely on physical signs and X-ray examination and measurement, the newborn check also pay attention to the following points:

(1) Appearance and multiple skin deformities with hip dislocation, the examiner often finds that the ratio of thighs to calves is not proportional, the thighs are short and thick, the calves are slender, often the hips are wide, the groin wrinkles are short or unclear, buttocks When the examination, the skin texture on both sides is different, and the affected side generally increases or increases one. When the lower limb is in the leveling agent, the limb valgus 15~20° is often shortened.

(B) the femoral head can not be touched, the hips bend the knees 90 ° one hand to hold the upper end of the calf, the other hand thumb to the inguinal ligament, the other 4 fingers set the hip ring jump, when the hand rotates the calf, under normal circumstances can be in front The activity and protrusion of the femoral head were found. When dislocated, the front of the emptiness and the four fingers behind the buttocks felt the femoral head active.

(3) Galeazzi (Galeazzi) lays the child supine, knees between the two lower limbs to 85 ° ~ 90 °, two flat symmetry, found that the knees have a high and low, called the Jiashi sign, femur shortening, hip This phenomenon occurs in all dislocations.

(4) Von Rosen line bilateral thigh abduction 45 ~ 50 ° and internal rotation, including the bilateral femur upper end to the pelvic anterior piece, for the bilateral femur central axis, and extended proximally, that is, Von Rosen line, normal This line passes through the upper anterior horn of the acetabulum; the dislocation of the anterior superior iliac spine, before the occurrence of the femoral skulling center, has certain reference value for diagnosis.

(5) Shenton line: the curved line of the lower pubic rim of the normal pelvic X-ray and the arc of the inner side of the femoral neck can be connected into a complete arc called the Xingdeng line. Where there is hip dislocation, subluxation In this case, the integrity of this line disappeared.

This line disappears in any dislocation, so it is impossible to distinguish between inflammation, trauma, congenital, etc., but it is still the simplest diagnostic method.

(6) Anterior lateral radiograph of the femoral neck: Occasionally, X-ray film is needed to further clarify the anteversion angle. The simplest method is to have the child lying flat and the hip up as a pelvic positive position. Similarly, the thigh is completely inside. Rotate the pelvic anterior radiograph, and compare the two slices to show the full length of the femoral neck when the internal rotation is complete. The femoral head is clear. When the hip bone is up, the femoral head overlaps with the size of the trochanter, and the presence of the anteversion angle can be estimated.

(7) Arthrography: Under normal circumstances, it is rare to perform joint angiography to confirm the diagnosis, but in some cases it is necessary to clarify the discoid cartilage, the stenosis of the joint capsule, and the reason for the failure of the reduction, angiography is occasionally necessary, Under anesthesia, the hip joint is sterilized by skin disinfection. The anterior joint of the acetabulum can be found to be detachable with 1-3 ml of 35% lipiodol contrast agent (diodone diodast). Under fluoroscopy, the outer edge of the acetabulum can be found to be barrier-free, and the cartilage of the outer edge of the acetabulum And the joint capsule with or without stenosis, if necessary, after the manual reduction can be angiographically confirmed whether the femoral head completely enters the acetabulum, the reduction and deformation of the discoid cartilage, due to complicated operation, insufficient contrast filling, difficult reading, less popular application in recent years Contrast diagnosis.

(8) Center edge angle (CE angle) It is often necessary to measure the degree of femoral head entering the acetabulum when visiting the case. Wibeng takes the center of the femoral head as a point, and the outer edge of the acetabulum is a point, even the two points are in line, hip The outer edge of the iliac crest is perpendicular to the downward line, and the two lines are obtusely angled at the central angle of the outer edge of the acetabulum. The normal range of this angle is 20 to 46°, with an average of 35°; 15 to 19° is suspicious; less than 15°, even Negative angle, indicating the external movement of the femoral head, dislocation or subluxation.

Diagnosis and diagnosis of congenital dislocation of the hip

The disease needs to be differentiated from congenital hip varus:

First, clinical symptoms and signs

1, common symptoms and signs:

The limbs were asymmetrical, the hips were widened, the groin wrinkles were asymmetrical, the affected side was short or disappeared, the hip pattern was also asymmetrical, the affected side was increased or more, the entire lower limb was shortened, and the Allis sign was positive.

2, different symptoms and signs

Infant hip varus is generally examined with limb shortening, large trochanter protruding outward, hip abduction, and internal rotation are obviously limited. It is an important clinical feature of infantile hip varus that is different from congenital dislocation of the hip. Hip dislocation The joint activities are unrestricted in all directions, often due to abnormal physical activity of the child, the limbs of the child are flexed, do not dare to straighten, the activity is worse than the healthy side, can be straightened when pulling, and then released after loosening Flexed, some children have external rotation, external position; or two lower limbs are crossed; even more, the hip is completely stiff, the most common limb shortening with buttocks, inner thigh or fossa skin wrinkles and deepening Or asymmetry, the perineum is widened, the affected limb is elastic, etc., Barlow test, Orrolani sign, Allis sign positive.

Second, imaging examination

1, X-ray inspection

(1) In the hip pelvic anterior segment of the child, the femoral neck dry angle is reduced, and the triangular bone is visible in the lower part of the femoral head. The boundary of the bone block is like a inverted "V" shaped translucent area. The tarsal plate under the bone, the lateral boundary is the dysplastic zone with increased X-ray transparency. This area grows with the child's age, and the body weight increases and becomes wider and more vertical. In the late stage, the greater trochanter becomes longer and hooks to the proximal end. It can form a pseudo joint with the tibia. The femoral head changes due to the reduction of the neck angle. The negative focus changes, the shape is also abnormal. The femoral head is twisted and oval, the acetabulum becomes shallow, and the infant type hip varus is not. The above performance.

(2) When the hip dislocation, Von2Rosen (abduction abduction) is abnormal, the child is supine, the lower extremity is abducted 45°, and the internal rotation is performed as much as possible. The normal extension of the femoral axis is through the acetabulum. The outer edge intersects below the plane of L5S1. When dislocated, the line intersects above the plane of L5S1 through the anterior superior iliac spine (Fig. 3 left). Individual children are abducted, the internal rotation position can be reset, and the result is normal.

2, CT examination

Because the femoral head cartilage can scan the image, the continuous scan of the head and sputum relationship is normal and the femoral neck dry angle is smaller. Those who consider the hip varus, the head lice relationship is definitely the hip dislocation, the three-dimensional reconstruction, the femoral neck is low and the elderly Consider hip varus, the upshift is the hip dislocation.

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