Hip dysplasia is a congenital disorder of the formation of the joint, which can cause dislocation or subluxation of the femoral head. There is either underdevelopment of the joint, or its increased mobility in combination with connective tissue insufficiency. At an early age, it is manifested by asymmetry of the skin folds, shortening and restriction of hip abduction. Subsequently, pain, lameness, increased fatigue of the limb are possible. Pathology is diagnosed on the basis of characteristic signs, ultrasound data and X-ray examination. Treatment is carried out using special means of fixation and exercises for muscle development.
Hip dysplasia (from Greek. dys — disorder, plaseo — form) is a congenital pathology that can cause subluxation or hip dislocation. The degree of underdevelopment of the joint can vary greatly – from gross violations to increased mobility in combination with weakness of the ligamentous apparatus. To prevent possible negative consequences, hip dysplasia should be detected and treated early – in the first months and years of the baby’s life.
Hip dysplasia is one of the widespread congenital pathologies. According to specialists in the field of traumatology and orthopedics, the average frequency is 2-3% per thousand newborns. Race dependence is noted: African Americans have it less often than Europeans, and American Indians have it more often than other races. Girls get sick more often than boys (about 80% of all cases).
The occurrence of dysplasia is caused by a number of factors. There is a clear hereditary predisposition – this pathology is 10 times more common in patients whose parents suffered from a congenital disorder of the development of the hip joint. The probability of developing dysplasia increases 10 times with pelvic presentation of the fetus. In addition, the likelihood of this pathology increases with toxicosis, drug correction of pregnancy, large fetus, lack of water and some gynecological diseases in the mother.
Researchers also note a link between the incidence rate and unfavorable environmental conditions. In ecologically unfavorable regions, dysplasia is observed 5-6 times more often. The development of dysplasia is also influenced by national traditions of swaddling babies. In countries where newborns are not swaddled, and the baby’s legs are in the position of retraction and flexion for a significant part of the time, dysplasia is less common than in states with traditions of tight swaddling.
The hip joint is formed by the femoral head and the acetabulum. In the upper part, a cartilaginous plate is attached to the acetabulum – the acetabulum lip, which increases the area of contact of the articular surfaces and the depth of the acetabulum. The hip joint of a newborn baby even normally differs from the joint of an adult: the acetabulum is flatter, located not obliquely, but almost vertically; the ligaments are much more elastic. The femoral head is held in the hollow thanks to the round ligament, the articular capsule and the acetabulum.
There are three forms of hip dysplasia: acetabular (violation of the development of the acetabulum), dysplasia of the upper parts of the femur and rotational dysplasia, in which the geometry of the bones in the horizontal plane is violated.
In case of a violation of the development of any of the departments of the hip joint, the acetabulum, articular capsule and ligaments cannot hold the femoral head in its proper place. As a result, it shifts outward and upward. At the same time, the acetabulum also shifts, finally losing the ability to fix the femoral head. If the articular surface of the head partially extends beyond the cavity, a condition called subluxation in traumatology occurs.
If the process continues, the femoral head shifts even higher and completely loses contact with the articular cavity. The acetabulum turns out to be below the head and wraps inside the joint. There is a dislocation. In the absence of treatment, the acetabulum gradually fills with connective and adipose tissue, which makes it difficult to correct.
Suspicion of hip dysplasia occurs in the presence of shortening of the hip, asymmetry of skin folds, restriction of hip abduction and the symptom of slipping Marks-Ortolani. Asymmetry of inguinal, popliteal and gluteal skin folds is usually better detected in children older than 2-3 months. During the inspection, they pay attention to the difference in the level of location, shape and depth of the folds.
It should be borne in mind that the presence or absence of this sign is not enough to make a diagnosis. With bilateral dysplasia, the folds may be symmetrical. In addition, the symptom is absent in half of children with unilateral pathology. The asymmetry of the inguinal folds in children from birth to 2 months is not informative, since it sometimes occurs even in healthy infants.
The symptom of hip shortening is more reliable in diagnostic terms. The child is placed on the back with his legs bent at the hip and knee joints. The location of one knee below the other indicates the most severe form of dysplasia – congenital dislocation of the hip.
But the most important sign indicating a congenital dislocation of the hip is the symptom of a “click” or Marx-Ortolani. The baby is lying on his back. The doctor bends his legs and wraps his thighs with his palms so that the II-V fingers are located on the outer surface, and the thumbs are on the inner. Then the doctor evenly and gradually removes the hips to the sides. With dysplasia on the diseased side, a characteristic push is felt – the moment when the head of the femur from the dislocation position is set into the acetabulum. It should be borne in mind that the Marx-Ortolani symptom is uninformative in children of the first weeks of life. It is observed in 40% of newborns, and subsequently often disappears without a trace.
Another symptom indicating the pathology of the joint is the restriction of movements. In healthy newborns, the legs are retracted to the position of 80-90 ° and are freely placed on the horizontal surface of the table. If the discharge is limited to 50-60 °, there are grounds to suspect a congenital pathology. In a healthy child of 7-8 months, each leg is allocated 60-70 °, in a baby with congenital dislocation – 40-50°.
With minor changes and no treatment, there may be no painful symptoms at a young age. Subsequently, at the age of 25-55 years, dysplastic coxarthrosis (hip arthrosis) may develop. As a rule, the first symptoms of the disease appear against the background of a decrease in motor activity or hormonal adjustment during pregnancy.
Characteristic features of dysplastic coxarthrosis are acute onset and rapid progression. The disease is manifested by unpleasant sensations, pain and restriction of movements in the joint. In the later stages, a vicious hip installation is formed (the leg is turned outward, bent and brought). Movements in the joint are severely limited. In the initial period of the disease, the greatest effect is provided by properly selected physical activity. With severe pain syndrome and a vicious hip installation, endoprosthetics is performed.
With an unrecorded congenital dislocation of the hip, a new defective joint is formed over time, combined with a shortening of the limb and a violation of muscle function. Currently, this pathology is rare.
A preliminary diagnosis of hip dysplasia can be made in the hospital. In this case, you need to contact a pediatric orthopedist within 3 weeks, who will conduct the necessary examination and draw up a treatment regimen. In addition, to exclude this pathology, all children are examined at the age of 1, 3, 6 and 12 months.
Special attention is paid to children who are at risk. This group includes all patients with a history of maternal toxicosis during pregnancy, a large fetus, pelvic presentation, as well as those whose parents also suffer from dysplasia. If signs of pathology are detected, the child is referred for additional studies.
The clinical examination of the baby is carried out after feeding, in a warm room, in a calm, quiet environment. To clarify the diagnosis, such techniques as radiography and ultrasonography are used. In young children, a significant part of the joint is formed by cartilage, which is not displayed on radiographs, therefore, this method is not used until the age of 2-3 months, and later special schemes are used when reading the images. Ultrasound diagnostics is a good alternative to X-ray examination in children of the first months of life. This technique is practically safe and quite informative.
It should be borne in mind that the results of additional studies alone are not enough to diagnose hip dysplasia. The diagnosis is made only when both clinical signs and characteristic changes are detected on radiographs and/or ultrasonography.
Treatment should begin at the earliest possible time. Various means are used to hold the child’s legs in the bending and retraction position: apparatuses, tires, stirrups, pants and special pillows. In the treatment of children of the first months of life, only soft elastic structures are used that do not interfere with the movements of the limbs. Wide swaddling is used when it is impossible to carry out a full-fledged treatment, as well as during the therapy of babies from the risk group and patients with signs of an immature joint detected during ultrasonography.
One of the most effective ways to treat young children are Pavlik’s stirrups – a soft fabric product, which is a chest brace, to which a system of special strips is attached, holding the child’s legs apart and bent at the knee and hip joints. This soft design fixes the baby’s legs in the right position and, at the same time, provides the child with sufficient freedom of movement.
Special exercises to strengthen the muscles play an important role in restoring the volume of movements and stabilizing the hip joint. At the same time, a separate set of exercises is compiled for each stage (dilution of the legs, keeping the joints in the correct position and rehabilitation). In addition, during treatment, the child is prescribed a massage of the gluteal muscles.
In severe cases, a single-stage closed reduction of the dislocation is performed, followed by immobilization with a plaster cast. This manipulation is performed in children from 2 to 5-6 years old. When a child reaches the age of 5-6 years, correction becomes impossible. In some cases, with high dislocations in patients aged 1.5-8 years, skeletal traction is used. If conservative therapy is ineffective, corrective operations are performed: open dislocation reduction, surgical interventions on the acetabulum and the upper part of the femur.
Prognosis and prevention
With an early start of treatment and timely elimination of pathological changes, the prognosis is favorable. In the absence of treatment or with insufficient effectiveness of therapy, the outcome depends on the degree of hip dysplasia, there is a high probability of early development of severe deforming arthrosis. Prevention includes examinations of all young children, timely treatment of the detected pathology.