Congenital abduction contracture of the hip

　　What causes congenital abduction contracture of the hip:

　　The etiology of this disease has not been fully clarified. Most believe it is caused by the incorrect position of the fetus in the uterus, leading to the contraction of the abductor muscle group (mainly the tensor fascia latae, gluteus maximus, gluteus medius, and gluteus minimus) and the external rotator muscle group, as well as the hip joint capsule. It is often not discovered after birth and is only paid attention to when walking. Some believe it is due to congenital muscle dystrophy of the abductor and external rotator muscle groups, or due to multiple muscle injections. Anatomically, the tensor fascia latae originates from the anterior superior iliac spine and the outer lip of the iliac crest, with the muscle belly in a fusiform shape, its fibers running downward and backward on the upper middle part of the femur, transforming into the iliotibial band. Its deep layer is attached to the lateral side of the joint capsule on the deep surface of the tensor fascia latae. The gluteus medius originates from the gluteal surface of the ilium and forms a flat fan-shaped muscle bundle, inserting into the greater trochanter. The anterior part is covered by the tensor fascia latae, and the posterior part is covered by the gluteus maximus. The gluteus maximus pulls the iliotibial band backward and upward, while the gluteus medius and minimus pull upward and inward along the superior margin of the greater trochanter, resulting in the abduction position of the lower limb and corresponding clinical manifestations.

　　What diseases can congenital hip abduction contracture be complicated with:

　　Due to the traction of the contracted gluteus medius and minimus, the affected limb is in an abducted and externally rotated position for a long time, while the healthy limb is in an adducted position, the femoral head and acetabulum are in a non-concentric position, leading to a decrease in the concentric pressure of the femoral head. The ipsilateral acetabulum may develop abnormally, and in severe cases, even subluxation of the femoral head may occur. At the same time, due to the traction of the contracted tissue on the pelvis, the pelvis tilts towards the affected side, causing secondary scoliosis, postural torticollis, and talipes varum and other deformities.

　　Some scholars have summarized this disease into three types:

　　1. Extension type:The main manifestation is the thickening and contracture of the fascia lata tensor muscle and the anterior edge of the gluteus medius, with the inability to bring the knees close together when extending the knee and hip.

　　2. Flexion type:The main manifestation is the contracture of the gluteus medius and the posterior edge of the fascia lata tensor muscle, and the gluteus minimus, with the inability to bring the knees close together when the hips and knees are flexed.

　　3. Mixed type:Both clinical manifestations of extension and flexion types are present.

　　How to prevent congenital hip abduction contracture:

　　If not treated in time after birth, it can lead to contracture of the hip abductor and external rotator muscles. However, in some cases, the shortening changes of the abductor muscles can disappear spontaneously. It is also necessary to pay attention that for patients after surgery, early exercise should be carried out, but excessive functional exercise may cause children to develop a fear of pain and refuse to exercise. Therefore, in clinical practice, appropriate timing should be selected according to the characteristics of children to ensure that the child can recover as soon as possible without leaving sequelae.

　　I. Physical examination

　　In a normal infant, when lying on the stomach and the hips are kept in a neutral position, the iliac crests on both sides are at the same level. However, in infants with hip abduction contracture, when lying on the stomach and keeping the hips in a neutral position, there is a pelvic obliquity, and the iliac crest on the affected side is significantly lower than that on the healthy side. The lower limb on the affected side is also longer than that on the healthy side. The spinous process of the lumbar vertebrae bulges towards the affected side, and there are gluteal dimples and不对称的popliteal creases. However, if the lower limb on the affected side is placed in abduction greater than 30°, these signs can completely disappear.

　　II. X-ray examination

　　X-ray examination can detect delayed ossification of the superior wall of the ipsilateral acetabulum on the anteroposterior pelvis film, which is related to the ipsilateral acetabulum being in the adducted position, and the pressure exerted by the femoral head on the center of the acetabulum decreases. If the abduction contracture is not corrected early, it can cause the ipsilateral hip to subluxate. X-ray examination can also exclude some deformities that cause pelvic obliquity, such as hemivertebrae at the lumbosacral region, congenital scoliosis, etc.

　　Congenital hip abduction contracture belongs to congenital diseases, generally with no special dietary requirements. It is recommended that patients eat light and nutritious food, avoid indigestible and刺激性 food, and avoid eating fried and greasy foods.

　　I. Non-surgical treatment

　　1. Non-surgical treatment:The main purpose of the massage and traction of the abductor and external rotator muscle groups is to relax the abductor, external rotator muscle groups and joint capsule, in order to alleviate clinical manifestations and achieve therapeutic effects.

　　2. Early Manual Therapy:Passive movement can achieve complete correction. The best time for treating this disease in the first two weeks after birth is to persist in passive traction of the contracted abductor muscle group, which is expected to be cured within four to eight weeks. During manual manipulation, place the baby in a prone position, keep the hip and knee of the healthy side flexed, so that the lumbar lordosis disappears. The operator's left hand stabilizes the pelvis and the healthy hip, and the right hand holds the knee of the affected side, trying to extend the hip joint as much as possible, then adduct and rotate the hip joint medially, and maintain this position for 10 seconds before relaxing. Repeat this process about 20 times, four to six times a day. For severe abductor muscle contracture, limb traction and double hip human-shaped plaster cast fixation are needed to maintain the position of adduction, extension, and internal rotation of the affected hip for three to four weeks.

　　2. Surgical Treatment

　　The incision is selected below the greater trochanter, because the pathological tissue is mostly located in the lower and outer part of the gluteus maximus, migrating to the iliotibial band, showing a 2-6 cm wide sheet-like contracture, mainly due to the degeneration and thickening of the fascia, and the degeneration of the gluteal muscle and joint capsule is relatively mild. The pathological changes are all 'obvious, degenerative muscles and nerve fibers'. Therefore, whether it is the flexion type or the extension type, the tense, degenerative, and contracted tensor fascia lata should be transversely cut, the lower limb is adducted in the position of extension of the hip and knee, attention should be paid to the fact that both iliac bones should be pressed down at this time to avoid the buttocks from leaving the bed and the pelvis from tilting, but it should be distinguished from the long-term history of pelvic tilt and even scoliosis. If it can exceed the midline and the middle and small gluteal muscles are not tense, and the knees can naturally be brought together in the position of flexion of the hip and knee, the operation is completed; if the simple cut of the tensor fascia lata still cannot adduct the lower limb, the upper extension of the incision can be continued to make a partial cut of the gluteus maximus, the middle and small gluteal muscle fibers contracted part, until the two lower limbs can cross over the midline in the position of extension, and the knees can naturally be brought together in the position of flexion of the hip and knee as the end; if the problem is still not solved, the contracted and degenerative joint capsule should be cut, and the joint capsule should be extended to achieve complete relaxation; for those with board-like contracture of soft tissue in the buttocks, if it is estimated that simple relaxation cannot solve the problem, an iliac spine incision can be made, the iliac outer plate can be stripped from the origin of the gluteal muscle and the origin can be shifted downward, the advantage is that it can both achieve good surgical results and prevent the weakness of extension of the hip and instability of the hip joint brought by extensive relaxation.