Osteoporosis

Introduction to osteoporosis Osteoporosis (osteoporosis) is a systemic bone disease characterized by decreased bone mass and microstructural destruction of the bone, manifested by increased fragility of the bone, and thus the risk of fracture is greatly increased, even for minor trauma or Fractures are also prone to occur without trauma. Osteoporosis is a chronic disease caused by multiple factors. There is usually no special clinical manifestation before the fracture occurs. More women than men, common in postmenopausal women and the elderly. basic knowledge The proportion of illness: 0.045% Susceptible people: good for the elderly Mode of infection: non-infectious Complications: fracture

Causes of osteoporosis

Endocrine factors (30%):

Female patients suffer from osteoporosis due to estrogen deficiency, and men are caused by decreased testosterone levels due to sexual dysfunction. Osteoporosis is particularly common in postmenopausal women. Premature ovarian failure causes osteoporosis to appear prematurely, suggesting estrogen Reduction is an important factor in the occurrence of osteoporosis. There will be a sudden and significant acceleration of bone loss in 5 years after menopause. It is common to lose 2% to 5% of bone loss every year. About 20% to 30% of early menopausal women lose bone mass. >3%/year, known as rapid bone loss, and 70% to 80% of women lose bone bone loss <3%/year, called normal bone loss, thin women are more prone to osteoporosis than fat women It is easy to fracture, which is the result of the conversion of androgen into estrogen in the adipose tissue of the latter. Compared with normal women of similar age, there is no significant difference in blood estrogen levels in patients with osteoporosis, indicating that estrogen reduction is not It is the only factor that causes osteoporosis.

Genetic factors osteoporosis (30%):

Osteoporosis is more common in whites, especially in Nordic countries, followed by Asians, while blacks are rare. Bone mineral density is an important indicator for the diagnosis of osteoporosis. Bone mineral density is mainly determined by genetic factors, followed by environmental factors. It has been reported that the difference in bone mineral density between young twins is four times that between single-oval twins; while the difference in bone mineral density between adult twins is 19 times that of single-oval twins, recent studies indicate Bone mineral density is closely related to the polymorphism of vitamin D receptor genotype. In 1994, Morrison et al reported that the vitamin D receptor genotype can predict the difference in bone mineral density, which can account for 75% of the total genetic impact, after various environmental factors. After adjustment, the bone density of bb genotypes can be about 15% higher than that of BB genotypes. In the incidence of vertebral fractures, bb genotypes can be about 10 years later than BB, and the incidence of hip fractures. On the other hand, the bb gene walker is only 1/4 of the BB type. The results of this study initially show that there are great differences among different races and countries. The final results still need further study. Others such as collagen gene and estrogen are affected. The relationship between genes and osteoporosis have also been reported, but there is no definite conclusion.

Nutritional factors (15%):

Calcium intake in adolescents has been found to be directly related to bone mass peaks in adulthood. Calcium deficiency leads to increased PTH secretion and bone resorption. Low-calcium diets are prone to osteoporosis, and vitamin D deficiency leads to mineralization of bone matrix. Impaired, osteomalacia can occur, long-term protein deficiency leads to insufficient synthesis of bone machinery protein, leading to backward new bone formation, such as calcium deficiency, osteoporosis is accelerated, vitamin C is the synthesis of bone matrix hydroxyproline Indispensable, it can maintain the normal growth of the bone matrix and maintain the bone cells to produce a sufficient amount of alkaline phosphatase, such as the lack of vitamin C can reduce bone matrix synthesis.

Disuse factor (10%):

The muscle exerts mechanical force on the bone tissue. If the muscular bone is strong, the bone density value is high. Because the activity of the elderly is reduced, the muscle strength is weakened, the mechanical stimulation is less, the bone mass is reduced, and the muscle strength is weakened and the coordination disorder is old. People are more likely to wrestle, and are prone to fractures when the bone mass is reduced. The elderly suffer from long-term bed rest after a moderate stroke, and bone loss is caused by disuse factors, which is prone to osteoporosis.

Osteoporosis prevention

Osteoporosis causes great inconvenience and pain to patients' lives. The treatment results are very slow. Once the fracture is life-threatening, special emphasis should be placed on the implementation of tertiary prevention:

Primary prevention: should start from children, young people, such as paying attention to reasonable diet and nutrition, eat more foods containing high Ca, P, such as fish, shrimp, shrimp skin, kelp, milk (250ml containing Ca300mg), dairy products, bone soup, eggs , beans, fine grains, sesame seeds, melon seeds, green leafy vegetables, etc., try to get rid of the "risk factor", adhere to a scientific lifestyle, such as insisting on physical exercise, more sunbathing, no smoking, no drinking, less coffee, strong tea and Contains carbonated drinks, eat less sugar and salt, animal protein should not be too much, late marriage, less fertility, lactation should not be too long, as much as possible to preserve calcium in the body, enrich the calcium pool, increase bone peak to the maximum is to prevent life later The best measures for osteoporosis, strengthen the basic research of osteoporosis, focus on high-risk groups with genetics, early follow-up, early prevention and treatment.

Secondary prevention: When people reach middle age, especially after menopause, bone loss is accelerated. During this period, bone mineral density examination should be carried out once a year. For people with rapid bone mass reduction, prevention and treatment should be taken early. Most scholars in Europe and America in recent years. It advocates long-term estrogen replacement therapy within 3 years after menopause, and insists on long-term preventive calcium supplementation to prevent osteoporosis safely and effectively. Japan advocates the use of active VitD and calcium to prevent bone mass. Loose, pay attention to active treatment of osteoporosis-related diseases, such as diabetes, rheumatoid arthritis, steatorrhea, chronic nephritis, hyperparathyroidism / hyperthyroidism, bone metastases, chronic hepatitis, cirrhosis.

Tertiary prevention: For patients with degenerative osteoporosis, drug treatment should be actively suppressed to inhibit bone resorption (estrogen, CT, Ca) and promote bone formation (active Vit D). Anti-fall, anti-collision and anti-mite should also be strengthened. Measures such as anti-bumping, active surgery for middle-aged and elderly patients with fractures, strong internal fixation, early activities, physical therapy, physical therapy psychology, nutrition, calcium supplementation, pain relief, bone growth, bone loss, immune function and overall quality Such as comprehensive treatment.

Osteoporosis complications Complications

1. Fracture: Osteoporosis fractures occur in daily activities such as reversing the body, holding objects, opening windows, etc., even if there is no obvious large external force, fractures can occur. The location of the fracture was the thoracic, lumbar vertebral body, distal radius and the upper end of the femur.

2, the most common and most serious complications of degenerative osteoporosis.

3, chest, lumbar compression fractures, posterior curvature of the spine, thoracic deformity, can significantly reduce lung capacity and maximum ventilation, patients often can have chest tightness, shortness of breath, difficulty breathing and other symptoms.

Osteoporosis Symptoms Common symptoms Diffuse osteoporosis Bone pain Gastrocnemius tendon pain Incisor spacing Increased spine Bone changes Bone metabolism Reduces limbs Long bones and muscles... Female lumbar pain hunchback thoracolumbar vertebral compression fracture

(1) Pain: The most common symptom of primary osteoporosis, which is more common in low back pain, accounting for 70%-80% of patients with pain. The pain spreads along the spine to the sides, and the pain is relieved when lying supine or sitting. When standing upright, stretching or standing for a long time, the pain is exacerbated during sedentary, the pain during the day is light, and it is aggravated when you wake up at night and in the morning, bending over, muscle movement, coughing, and exacerbation when the stool is forced. Generally, when the bone mass is lost by more than 12%, Bone pain can occur, senile osteoporosis, vertebral trabecular atrophy, reduced number, vertebral compression deformation, spine flexion, lumbar muscle to correct spine flexion, double contraction, muscle fatigue and even paralysis, pain Newly thoracic and lumbar vertebral compression fractures can also produce acute pain. Spinal spinous processes in the corresponding parts can have strong tenderness and snoring pain. Generally, they can be gradually relieved after 2-3 weeks. Some patients may have chronic low back pain. The spinal nerve can produce radiation pain in the extremities, sensory dyskinesia in both lower extremities, intercostal neuralgia, post-sternal pain similar to angina pectoris, and upper abdominal pain similar to acute abdomen. If the spinal cord is compressed, the horsetail affects the bladder and rectal function.

(B) shortened length: hunchback, more often after pain, the front of the vertebral body is almost composed of cancellous bone, and this part is the body of the pillar, the weight is large, especially the 11th, 12th thoracic vertebrae and the third lumbar vertebrae, The load is larger, it is easy to compress and deform, the spine is inclined forward, the back curvature is intensified, and the hunchback is formed. With the increase of age, the osteoporosis is aggravated, and the kyphosis curvature is increased, resulting in significant knee joint paralysis. Each person has 24 vertebrae. Body, the height of each vertebral body of a normal person is about 2cm. When the elderly are osteoporosis, the vertebral body is compressed. Each vertebral body is shortened by about 2mm, and the body length is shortened by an average of 3-6cm.

(3) Fracture: This is the most common and serious complication of degenerative osteoporosis.

(4) Decreased respiratory function: chest, lumbar compression fracture, posterior curve of the spine, and thoracic deformity can significantly reduce lung capacity and maximum ventilation. Patients often have chest tightness, shortness of breath, and difficulty breathing.

(5) Measurement of bone density.

Osteoporosis examination

Laboratory inspection

1, biochemical examination of serum calcium, phosphorus, ALP and hydroxypurine (lysine) more normal.

2, concurrent fractures may have a decrease in blood calcium and elevated blood phosphorus, and some patients have increased urinary calcium excretion. Blood PTH, vitamin D, cAMP, etc. are generally normal.

3, metabolic balance test shows negative calcium, negative magnesium and negative phosphorus balance, but the cause of negative balance may be reduced intestinal absorption or increased urinary excretion, or both.

4, secondary osteoporosis has a biochemical abnormality of the primary disease.

Auxiliary inspection

1. X-ray examination of osteoporosis on the X-ray film, the basic change is the reduction of the number of trabecular bone, thinning and cortical thinning. The fine trabecular bone is clearly visible, which is completely different from the rough and fuzzy trabecular morphology caused by softening of the bone. The skull is thin, multiple spotted translucent areas appear, and the saddle back and saddle bottom become thin. The density of the dense line of the hard plate decreases or disappears, the bone density of the vertebral body of the spine decreases, the bi-concave deformation occurs, the intervertebral space widens, the anterior edge of the vertebral body is flat, and the wedge shape (vertebral compression fracture); the growth obstacle line of the long bones of the extremities obvious. Osteoporosis is associated with fractures and bone deformities, such as femoral neck fractures, ribs, pelvic fractures and deformities. Patients with osteoporosis during growth and development may have broad calcifications, horns and spurs at the metaphysis.

2. Osteoporosis index measurement can determine the presence or absence of osteoporosis. However, its sensitivity is poor. It is difficult to find patients with early osteoporosis.

3, bone density measurement

(1) Single photon absorption bone density measurement: The single photon absorption method can not only reflect the bone mineral content at the scanning site, but also indirectly understand the bone density and weight of the whole body bone. The advantage is that the patient is painless, the amount of radiation received is very low, simple and easy, low cost, and can be repeated many times. The sensitivity is 1% to 3%, and the coefficient of variation of the measured value is 1% to 2%.

Single-photon absorption BMD measurement mainly reflects changes in cortical bone. The changes in vertebrae and trabecular bone are poorly reflected. Even with the trabecular bones as the measurement site, it is difficult to understand the changes of the vertebral trabeculae.

(2) Two-photon absorption method Bone density measurement: Two-photon absorption scanning was performed at two locations using 153 Gd to measure the BMC of the femoral neck and vertebrae. Since osteoporosis occurs first in the small tibia, osteoporosis can be detected earlier than the single photon absorption method.

(3) CT BMD measurement: At present, there are mainly two CT bone density measurement methods, namely single energy CT bone mineral density measurement (SEQCT) and dual energy CT bone mineral density measurement (DEQCT). This method is mainly used for the determination of bone mineral density of vertebrae, and can directly display the cross-sectional image of the vertebrae. The accuracy of DEQCT is higher than that of SE-QCT, which is more accurate than the former.

(4) Dual-energy X-ray absorption measurement: Dual-energy X-ray absorption (DXA) is the most commonly used method for measuring bone mineral density (BMD) and bone mineral content (BMC). It has high degree of automation and low radiation radiation. Short scan time, high accuracy and precision.

Diagnosis and diagnosis of osteoporosis

diagnosis

The diagnosis of postmenopausal and senile osteoporosis, first need to rule out secondary osteoporosis caused by various other reasons, such as hyperparathyroidism and multiple myeloma, osteomalacia, renal bone Malnutrition, osteogenesis in children, metastases, leukemia, and lymphoma.

Graded diagnosis of osteoporosis: normal BMD or BMC within 1 standard deviation (SD) of normal adult bone mineral density; osteopenia for BMD or BMC is 1 to 2.5 lower than normal adult bone mineral density Standard deviation; osteoporosis is more than 2.5 standard deviations of BMD or BMC than normal adult bone mineral density; severe osteoporosis is more than 2.5 standard deviations lower than BMD or BMC than normal adult bone mineral density with One or more fragility fractures. BMD or BMC can be measured in the central axis or peripheral bone in this diagnostic criteria.

Differential diagnosis

Mainly differentiated from osteomalacia, myeloma, osteogenesis imperfecta and various cancerous bone diseases.

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