Hand small square

Introduction Hand small square is one of the clinical manifestations of Kashin-Beck disease. Kaschin-Beck disease can cause short-finger (toe) malformation symptoms, and knuckles develop shorter than normal people. Kashin-Beck disease (Kaschin-Beck disease) is an endemic disease. Popular in northern China. The disease was first discovered in the northeast and later found in the northwest. In the northwest region, it is also known as willow disease. Most of the epidemics are concentrated in one area and become an infected area. Most of the disease occurs in adolescence, males are more common, leaving the epidemic area at an early age, rarely ill, leaving the epidemic area after 12 years old, can also get sick, but the onset is later.

Cause

The etiology of Kashin-Beck disease has not yet clarified that there are mainly three kinds of etiology in the present and the outside.

a biogeochemistry

Originally, the former Soviet scholars suggested that the disease was caused by too much, insufficient or imbalanced one or several elements. In the early days, it was thought to be related to less calcium and water in the soil and water. Later, it was claimed that the disease caused by excessive phosphorus and manganese in the soil and the main and non-staple foods in the ward. These have failed to find the exact basis in human patients or in experimental studies.

Chinese scientists have found that Kaschin-Beck disease is closely related to low-energy selenium in the environment: (1) The distribution of the diseased area in China is generally consistent with that of the low selenium soil. The total selenium in the soil of most wards is below 0.15mg/kg, and the content of selenium in food is low. At 0.020mg/kg; 2 the blood and urine hair selenium content of the ward is lower than that of the non-disease group, and a series of metabolic changes associated with low selenium can be detected in the patient; 3 when the hair selenity level of the ward is rising, the condition Decline; 4 after selenium can reduce the new incidence of Kashin-Beck disease to promote the repair of metaphyseal lesions.

However, there are some important facts that do not support low selenium is the cause of this disease: 1 in some areas, low selenium does not occur in Kashin-Beck disease, such as Yulin, Luonan in Shaanxi, and some Keshan disease areas in Yunnan, Yunnan; in some places, selenium is not very Low, but this disease occurs, such as Zuoquan, Huo County in Yidu, Shanxi, and Zebra in Qinghai, Ankang, Shaanxi; 2 can not completely control the new development of this disease after selenium supplementation; 3 cell culture shows that chondrocytes There is no special need for growth of selenium; 4 animal experiments with low selenium can not cause cartilage necrosis similar to this disease.

At present, more people tend to think that low selenium is only a conditional factor in the onset of this disease.

Two mycotoxins

Residents of toxic substances that are believed to be contaminated with certain Fusarium bacteria and form heat-resistant wards are sick from eating foods containing this type ofmycin. This theory was first proposed by former Soviet scholars between 1943 and 1945. It has not been widely recognized by the academic community. After the 1960s, Chinese scholar Yang Jianbo and others continued to conduct research in this area, noting that the most detected fungi in the ward corn was Fusarium oxysporum; and the presence of a large amount of sickle metabolites, threitol and xylitol, in the corn meal and flour of the ward, has a "dose effect" relationship with Kaschin-Beck disease. The Fusarium isolated from the ward of the ward is inoculated into the non-disease corn to make the granules, and the addition of 10% to the normal beverage to feed the chicks can cause the cartilage of the knee joints of the chicks.

The main problems currently faced by mycomycin are: 1 How to explain the close-range focal distribution of the ward in epidemiology, it is difficult to make a convincing explanation by temperature, humidity, grain harvesting and storage conditions; The strains are not the same (for example, the dominant species isolated from some wards are Alternaria alternata instead of Fusarium). The difference between the ward and the non-disease interval is not regular; 3 cell culture proves that Fusarium toxin (For example, TDP-1 and P. serrata T-2 of Fusarium oxysporum) have no selective toxic effects on chondrocytes.

Three organic poisoning

It is believed that this disease is caused by humus pollution in the ward, and many people in China have long attributed the cause of this disease to poor water quality. Japanese scholar Yan Ze and others studied the relationship between plant organic matter in drinking water and Kashin-Beck disease. It is believed that ferulic acid in the organic matter may be a causative factor for hydroxycinnamic acid.

In the scientific investigation of the Kaschin-Beck disease in Yongshou County of China from 1979 to 1982, the total amount of humic acid and hydroxyhumic acid in water was positively correlated with the lesion rate of Kashin-Beck disease, and negatively correlated with selenium content. In recent years, the isolation and identification of organic matter in the drinking water of the ward shows that there is no significant difference between the core parts of the humic acid structure in the ward and the non-disease area. Small molecular organics such as phenolphthalein, sulfur and nitrogen benzothiazoles are in the ward. In the drinking water, the occurrence of spin resonance (ESR) was detected, and it was found that there was obvious free radical signal in the drinking water of the ward.

In recent years, some scholars believe that low selenium, mycotoxins and organic matter in drinking water may have an intrinsic link in the disease. That is, the common result of the contamination of food by fungi and the contamination of drinking water by organic matter all produce free radicals (half-free radicals). The increased free radicals can damage the chondrocytes into the human body; the lack of sufficient selenium protection in the ward environment Under, it causes the disease.

The main problem facing this view is why free radicals and peroxidative damage only selectively act on chondrocytes without causing significant damage to other tissues.

Four experimental animal model studies

In order to explore the etiology and pathogenesis, many scholars at home and abroad have devoted themselves to the study of experimental animal models of this disease.

Chinese researchers generally use cartilage damage as the basic morphological index for determining animal models. However, in the past experiments with rats or dogs, most of the seesaw and articular cartilage were scattered chondrocyte necrosis and matrix degeneration. Small cell-free areas and other minor changes in the characteristics of the lack of qualitative differences compared with the control group, so it is difficult to judge its value. In recent years, it has been successful in experiments conducted in the ward and food of the Ganges. A series of secondary changes in the deep layers of articular cartilage and epiphyseal cartilage in most monkeys after feeding with water or grain in the ward for 6 months or 18 months, basically reproduces a large number of secondary changes. The pathological development process of bone joint disease and the main pathological characteristics of the experimental results suggest that there are pathogenic factors in the water and grain of the diseased area; the pathogenic effect of such pathogenic factors on experimental animals has not weakened with the disease condition of the diseased area; Water alone can also cause obvious cartilage necrosis, so the basic cause is not like the lack of certain trace elements.

It has not been proven so far that there is a naturally occurring Kaschin-Beck disease in the animal kingdom. In the past, the joints of livestock or dogs in the ward have been swollen and cautious, and they are far from the Kaschin-Beck disease of humans. Two foreign countries mentioned that they can compare with this disease. :

(1) Osteochondrosis of livestock: This disease is similar to Kaschin-Beck disease in the development of articular cartilage and epiphyseal cartilage necrosis and development of secondary osteoarthrosis, but its most typical change is chondrocyte Differentiation disorders and local hypertrophic chondrocyte accumulation, which is different from Kashin-Beck disease. Although Kaschin-Beck disease can be seen as uneven thickness of the tarsal plate, the existing materials have not been proven to be the basis for the accumulation of hypertrophic chondrocytes before cartilage necrosis.

(2) Tibial dyschondroplasia in birds: The basic lesion is that the epiphyseal cartilage matrix cannot stop calcified cartilage internalization. Although it is sometimes considered to be equivalent to osteochondrosis of livestock, it has no commonality with human Kashin-Beck disease because there is no cartilage necrosis and the articular cartilage is not tired.

an examination

Related inspection

CT examination of bone and joint soft tissue

Short finger (toe) malformation: knuckle development is shorter than ordinary people, hand small square. Or because of the different degree of developmental disorders of each finger (toe), the length of their fingers loses normal proportional relationship with each other.

Differential diagnosis

Differential diagnosis should be made with various deformities of the fingers;

1. Flexion refers to the change of flexion deformity of the finger, the flexion of the finger, often a family history, the beginning is not obvious, gradually worsening, often accompanied by other systemic syndromes such as Doun syndrome.

2. Giant finger (toe) Giant finger (toe) is a congenital malformation characterized by an increase in the volume of the fingers or toes. The incidence in congenital malformations of the extremities is very low, about 0.9%.

Short finger (toe) malformation: knuckle development is shorter than ordinary people, hand small square. Or because of the different degree of developmental disorders of each finger (toe), the length of their fingers loses normal proportional relationship with each other.

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