Cysticercosis of bone

Introduction to bone cysticercosis Skeleton cysticercosis refers to a parasitic disease in which larvae of Echinococcus granulosus (Echinococcus) are parasitic in the bone. The disease occurs in animal husbandry areas, and direct contact with dogs is the main form of human infection. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of transmission: insect vector transmission Complications: paraplegia

Cause of bone cysticercosis

The disease is caused by parasitic parasites (Echinococcus granulosus), which are parasitic in the end-host dog, wolf and other small intestines, and the eggs are excreted from the feces. The intermediate host is human and cattle, sheep, horses, etc., if swallowed In the eggs, the six hooks are hatched in the gastric juice digestion, and the intestinal wall is inserted into the mesenteric vein or lymphatic vessels. After reaching the liver, about 75% of the six hooks are retained in the liver, and the rest are passed through the right heart into the lungs. And stay in the lungs, only a small part of the six hooks into the large circulation, and in the bone, brain and other parts to produce lesions, the formation of hydatid (Echinococcus), the formation of bone cysticercosis in the bone.

The disease occurs in the livestock area, and direct contact with the dog is the main way for people to be infected, because the dog eats raw cattle, the opportunity of mutton and the chance of cattle and sheep eating dog dung, and the direct contact between the pastoral area and the dog is another chance. Many, therefore, easy to cause the epidemics of cysticercosis, and the incidence of cysticercosis is 1% to 2%, and because the cysticercosis develops slowly in the bone, it often appears 10 to 20 years after infection. Clinical symptoms, so there are very few symptoms in childhood, the incidence is more than 30 to 50 years old, the lesions are mostly in the pelvis, spine, femur, tibia, fibula and other parts.

Osteocysts prevention

prevention

Human cysticercosis is often transmitted by dogs. It is necessary to control the raising of dogs, strengthen the management of livestock, and strictly prevent the breeding of raw cattle, sheep and horse meat with cysticercosis, pay attention to personal hygiene, not drinking raw water, raw milk, especially In the pastoral area.

Complications of capsular cysticercosis Complications

The disease often combines with other parts of the disease. If the spine is involved, the cyst can compress the spinal cord or nerve root, then the symptoms and signs of nerve damage appear, and even paraplegia occurs. The late cyst penetrates the cortical cortex and invades the surrounding soft tissue, which may appear clinically. Large masses, if worn through the skin, can be secondary infection, fistula can be long-term outflow of pus and fragments of hydatid, difficult to heal, clinically, there are few cases of joint invasion, and when involved, can lead to pathological dislocation.

Patients with osteoid echinococcosis often have lesions in other parts of the liver, lungs, and brain.

Symptoms of cysticercosis common symptoms bone pain muscle atrophy spine and extremities deformity secondary infection paraplegia

The clinical symptoms and signs of cysticercosis: determined by the size of the cyst and the location of the cyst, generally due to bone hydatidosis, the majority of patients have been advanced, often due to the incidence of rational fractures.

In the early stage of the disease, the growth of the six hooks in the bone tissue is slow, and there is no discomfort for a long time. Very few people with mild pain are often not taken seriously. When the lesion continues to develop, bone pain, lameness, local or limb muscle atrophy may occur. The cyst infiltration destroys more bone, the pain is aggravated, the affected bone can be thickened, deformed, and a slight external force can produce pathological fracture. Patients can often come to see a doctor at this time. If the spine is involved, the cyst can be oppressed. Spinal cord or nerve root, there are symptoms and signs of nerve damage, and even paraplegia, late cysts penetrate the cortical bone into the surrounding soft tissue, clinically there may be large masses, if worn through the skin, secondary infection, fistula can be Long-term outflow pus and fragments of hydatid are difficult to heal, and there are few cases of intra-articular invasion in the clinic. When involved alone, it may lead to pathological dislocation.

Patients with osteoartia often have liver, lung, brain and other parts of the disease, so it should be carefully examined.

Examination of osteocystis

The following auxiliary examination methods are conducive to the diagnosis of this disease:

1. Intradermal test of cystic fluid (Casoni skin allergy test) The diluted cystic fluid is used as an antigen and injected intradermally into the forearm of the patient to induce local allergic reaction with an accuracy of more than 90%. The test has not only diagnostic value. You can also check the treatment effect.

2. The cysticercosis complement test (Weingerg test) clinically often uses the human body's immune response to cystic cysts for serological examination, complement complement test, the positive rate can reach 90%, especially after cyst rupture or surgical treatment The positive is higher because the body absorbs more cystic fluid antigens.

3. The increase of eosinophils in blood examination can be used as an auxiliary reference.

4. X-ray performance: the affected bone is erosive-like irregular erosion, the trabecular bone is destroyed and there is a cystic transparent area, which is connected with a "grape-like", surrounded by trabecular bone, normal bone and diseased bone. There is no obvious dividing line, the shape of the early bone is normal, the area of the late cystic bone is enlarged, the thickness of the cortex is different, the backbone can be slightly thickened, but there is no new bone formation and periosteal reaction. This is characteristic of the spine when it is involved. There may be a false paravertebral abscess image, which is caused by the protrusion of the cyst to the paravertebral soft tissue on both sides. Generally, the intervertebral disc is not invaded. This point can be used to distinguish from spinal tuberculosis. When the flat bone is involved, the lesion is more obvious. Early X-ray findings should be differentiated from osteosarcoma, neurofibromatosis, vertebral hemangioma, giant cell tumor, bone cyst and other diseases.

Diagnosis and identification of cystic echinococcosis

Can be based on the history of living in the epidemic area, and has frequent contact with dogs and sheep; clinical and X-ray performance characteristics; laboratory test positive results, etc., but should be associated with giant cell tumor of bone, fibrocystic osteitis, osteosarcoma and spine Identification of tuberculosis.

Because Echinococcus granulosus can be parasitic in various parts of the body, the incidence is different, so it is necessary to identify a variety of diseases with similar symptoms. The diseases that need to be identified are commonly the following:

1. osteolytic tumors;

2, bone cysts;

3. Aneurysmal bone tumor;

4. Giant cell tumor of bone;

5, fibrous cystic osteitis;

6, osteosarcoma;

7, spinal tuberculosis and so on.

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