Developmental deformity

Introduction Congenital malformations and developmental malformations refer to abnormalities or potential abnormalities at birth or before birth. Humans can have certain differences in anatomy, but generally do not cause adverse consequences. If the anomaly is outside the normal range, the well has a certain effect on morphology and function and should be subordinate to congenital or developmental malformations. The main reasons are: 1 occurs in the uterus, which is obvious after birth, which is the true formation of the first major. 2 single gene replacement or mutation disorder. 3 environmental factors or some factors in the prenatal period, causing complex changes, which often cause severe fetal distortion in the early 4 weeks of pregnancy.

Cause

Congenital and developmental malformations can have three causes:

1 occurs in the uterus, which is obvious after birth, which is the true formation of the first major.

2 single gene replacement or mutation disorder.

3 environmental factors or some factors before the birth, causing complex changes, which often cause severe fetal distortion in the early 4 weeks of pregnancy, such as rubella infection, aminopterin, thalidomide (reaction stop thalidomide) and other drugs Use of etc. At this stage, the fetus is in an active stage of cell differentiation, and the mother's endocrine and nutrient environment is also in a stage of significant change, and any external disturbances will lead to malformation.

The factors that cause malformation are:

1 mechanical depression. This is only seen in the second trimester. In the last 10 weeks of pregnancy, the fetus grows rapidly, and the amniotic fluid gradually decreases. At the same time, the pressure in the abdominal cavity and pelvic cavity gradually increases. Especially the twin or uterine malformation and the uterine fibroids can limit the fetal activity, resulting in poor formation, such as congenital. Dislocation of the hip, deformity of the foot, arch deformity of the lower leg, torticollis, etc.

2 genetic factors. Some syndromes or defects of skeletal developmental disorders and malformations can be found by chromosomal examination. Generally divided into three categories: single gene abnormalities, chromosomal disorders and multifactorial inheritance (the latter including genetic and environmental factors).

an examination

Related inspection

CT examination of bones and joints of limbs and joints

1. First diagnose whether it is a congenital malformation. This is obvious after birth. This is a true first-generation abnormality.

2. Perform a chromosome check to find the cause of the disease.

3. Ultrasound examination: Ultrasound is the most recognized and important examination method for screening and diagnosing fetal structural abnormalities, especially in the examination of fetal heart abnormalities. Ultrasonography is also an important means of routine prenatal screening. In addition, ultrasound examination of fetal blood flow changes has also become an important method to detect intrauterine safety.

4. Fetal magnetic resonance examination: Magnetic resonance has a broad prospect in the application of obstetrics because of its multiple imaging, high resolution of soft tissue, no radiation, and safety to the fetus. It has become an important verification and supplementary diagnostic tool for fetal abnormalities found in ultrasound examination in prenatal diagnosis. Especially in the diagnosis of fetal central nervous system abnormalities, such as the identification of cerebral hemorrhage and other aspects have a more prominent performance.

Differential diagnosis

Congenital malformations can be summarized according to the formation mechanism:

(1) Differentiation defects: The embryonic primordia cannot form the part it should form. If it occurs in the embryonic stage, this part is absent; if it occurs in the late stage of development, the primordium of the bone cannot undergo cartilage formation and bone formation. For example, multiple endogenous chondromatosis, bone development stays in the cartilage stage.

(2) Segmental defects: A striking example is congenital fusion, in a combined state, such as congenital cervical spine deficiency or fusion (Klippel-Feil syndrome), congenital rib fusion, anterior ulnar ulnar bone connection, and (toe) and so on.

(3) ossification center fusion defects: such as congenital clavicle pseudo joint, two-point tibia and so on.

(4) Movement defects: such as congenital high scapula is due to the failure of the scapula to reduce and maintain the deformity caused by the neck.

(5) Excessive parts: such as multi-finger (toe) deformity.

(6) Structural defects of bone: This type includes many hereditary dysplasias. According to the Paris classification of 1969, this group of bone development abnormalities were divided into:

1 systemic bone diseases with unclear pathogenesis, such as abnormal development of osteochondral, developmental disorders, idiopathic bone dissolution and primary growth disorders.

2 systemic bone diseases with clear pathogenesis, such as chromosomal abnormalities, primary metabolic abnormalities, mucopolysaccharidosis, mucoidosis and other metabolic extra-osseous disorders.

3 bone abnormalities secondary to extramedullary system disorders.

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