Osteoporosis in the elderly

Introduction to osteoporosis in the elderly Primary osteoporosis refers to a reduction in bone unit volume, degeneration of bone tissue, and increased fragility of the bone, resulting in systemic bone disease that is prone to fracture. The new definition emphasizes bone mass, bone loss and bone structure. importance. It includes not only osteoporosis in those who have suffered fractures, but also preclinical osteoporosis with potential fracture risk. basic knowledge The proportion of sickness: 0.01% Susceptible people: the elderly Mode of infection: non-infectious Complications: fracture

The cause of osteoporosis in the elderly

Genetics (20%):

The level of peak bone mass is related to genetic factors.

1 Race: Caucasians and Asians have lower peak bone mass and are at greater risk of developing osteoporosis.

2 Family history: The bone density of young women is significantly correlated with their parents' bone mineral density.

3 The bone density of identical twins has greater similarity.

4 Vitamin D congenital deficiency is often accompanied by a decrease in bone density.

Nutrition (20%):

Appropriate intake of calcium can increase bone density and reduce the risk of osteoporosis. The absorption rate of calcium intake is 75% in childhood and 30% to 50% in adults. Calcium supplementation in early adult can be Increase bone mineral quality, intake disorders are associated with reduced bone density, the United Nations FAO and the World Health Organization recommended daily intake of 500mg, US nutritionists recommend 800mg, Chinese nutritionists recommend the use of US calcium Into the standard, childhood, pregnancy and lactation calcium intake should be increased to 1000 ~ 1500mg per day.

Exercise (20%):

Exercise can stimulate bone to improve circulation, bone mass maintenance or bone hypertrophy depends on the type of exercise, frequency and anti-gravity effect, adolescent exercise can increase bone mineral quality, but excessive exercise can not only increase bone mineral quality, but reduce bone Mineral quality, which must be avoided, at the same time, the movement must be regular, persevere, if the intensity or frequency of exercise is reduced, the effect of exercise on the bone will also be reduced.

Endocrine status (20%):

(1) menstrual cycle and estrogen and progesterone can lead to changes in bone mineral quality: the earlier the menarche, the greater the quality of bone minerals thereafter, the later the menarche, the smaller the bone density, the women who stop ovulation than the women who continue to ovulate Bone mineral density is low, women are mainly estradiol before menopause, and mainly estrone after menopause. The conversion process of estrogen is mainly done in fat. Therefore, obese women are less likely to suffer from osteoporosis than women who are thin. The effect of estrogen on bone, one is to affect osteoblasts, increase the number of osteoblasts, increase the synthesis of collagen by osteoblasts, increase the number of prostaglandin receptors on osteoblasts, and secondly inhibit osteoclasts on bone. In addition, estrogen can also inhibit the activity of parathyroid hormone, stimulate the secretion of calcitonin, promote the absorption of calcium in the gastrointestinal tract and promote the conversion of vitamin D to the active mode.

(2) Parathyroid gland: secreted by parathyroid hormone, the hormone can increase the number and activity of osteoclasts and osteoblasts. When the parathyroid hormone is excessively secreted, bone turnover accelerates, but as long as the bone is broken/osteogenesis The cells maintain a balanced activity and the bone mass does not decrease.

(3) Vitamin D: The active form of vitamin D is 1,25-dihydroxyvitamin D3, which has two functions. One is to promote the absorption of calcium and phosphorus in the intestine, and the other is to increase the activity of osteoclasts in the bone regeneration site. It can stimulate the synthesis of protein in osteoblasts and participate in the mineralization of bone matrix. The lack of vitamin D will lead to osteoid mineralization disorder and osteomalacia, but vitamin D excess will cause bone loss.

(4) Calcitonin: Calcitonin is secreted by parathyroid C cells, whose main physiological function is to inhibit the activity of osteoclasts, and pharmacological application can reduce the rate of bone turnover.

(5) Thyroxine: T3, T4 can affect bone cell function through direct or indirect pathways. Hyperthyroidism can lead to increased bone resorption sites and enhanced bone resorption, causing bone mineral loss, and bone cells are extremely sensitive to exogenous thyroxine.

(6) Glucocorticoids: There are glucocorticoid receptors on bone cells, and excess hormonal activity will lead to inhibition of osteoblast function.

(7) Androgen: Male patients with hypogonadism often suffer from osteoporosis. Osteoporosis can be prevented by supplementation with androgens. Androgen plays a more physiological role in postmenopausal women. Studies have shown that the combination of estrogen and hormone therapy for osteoporosis is more effective than estrogen alone.

Pathogenesis

The bone is composed of cortical bone (bone density) and cancellous bone (bone cancellous).

Cortical bone: There are 3 different levels, namely the endosteal layer, the periosteal layer and the cortical inner layer. The degree of activity and location of bone remodeling is related to the age stage. In childhood, the rate of new bone formation in the periosteum is greater than that of the endosteal layer. Destruction speed, a net increase in bone mass in the outer layer of bone, puberty, new bone formation in both the endosteal layer and the periosteal layer, increasing the total amount of bone, and increasing bone loss in the endometrial layer in early adulthood. Subperiosteal bone begins to over-align, suggesting the onset of age/menopausal-associated bone loss, accompanied by narrowing of the cortical bone layer and widening of the medullary cavity.

The bone unit is the Harvard system, which is the main structural unit of the long bone. It is arranged longitudinally in the long bone and can be connected to each other. It is the main part of the support of the dense bone.

Cancellous bone: The trabecular bone is composed of parallel and vertically aligned bone plates and bone cells. The direction of the bone plate is consistent with the pressure and tension direction of the bone. The bone reconstruction occurs in the bone plate of each trabecular bone. Inside and outside, over-reconstruction will lead to thinning of the bone plate and eventually dissolution of the bone tissue, which will lose the structural continuity of the trabecular bone. This change was first seen in the parallel trabecular bone, which in turn led to a decrease in the mechanical strength of the bone. The probability of fracture due to gravity is significantly increased, and the changes in trabecular bone structure and accompanying changes in vertebral pressure increase with age.

Bone rebuilding: bone renewal determines the strength of the bone, the old bone is fragile, and the new bone is strong. Therefore, the reconstruction process of the bone is to remove the old bone, form new bone, metabolism, and maintain the bone strong. The cells involved in renewing the bone are mainly Osteoclasts and osteoblasts.

Osteoclast

Osteoclasts are composed of multiple monocytes. When they are active, they can release a variety of proteases, carbonic anhydrase, lactic acid and citric acid. They dissolve bone minerals and bone matrix under the action of enzymes and acids. Therefore, osteoclasts have the function of dissolving and absorbing bone minerals and bone matrix. The differentiation of osteoclasts, supplementation and inhibition are affected by various hormones. Among them, hormones that promote osteoclast activity are parathyroid hormone, white. Triene, transforming growth factor- (TGF-), tumor necrosis factor (TNF) and interleukin-1 (IL-1), etc., hormones that inhibit osteoclast activity are estradiol, calcitonin, Y - Interferon (Y-IFN) and TGF-, osteoclasts have estrogen receptor estrogen, and the most important role of inhibition of absorption factors is to inhibit the differentiation and supplementation of osteoclasts, and secondly to inhibit its activity.

Osteoblast

Osteoblasts are distributed on the surface of bone tissue, more adulthood, less in adulthood, and osteogenic cells secrete organic matrix of bone matrix, which is rich in type I collagen, ready for subsequent ossification. Osteoblasts also release matrix vesicles to calcify bones. Osteoblasts are also controlled by a variety of hormones. Among them, factors that promote osteoblast activity are 1,25-hydroxyvitamin D3, TGF-, thyroid hormone, Estradiol, human growth factor, prostaglandin E2 and parathyroid hormone; only adrenal cortex hormones that inhibit osteoblast activity, and estrogen receptors on osteoblasts, found in vitro, estrogen can be osteogenesis Cells produce the following effects:

1 increase the number of osteoblasts.

2 increase the amount of collagen synthesis in osteoblasts.

3 increase the receptor density of steroid hormones on the nucleus.

4 Increase the amount of messenger RNA that guides the synthesis of TGF- by osteoblasts.

5 inhibit parathyroid hormone-related CAMP production.

The bone rebuilding cycle is a process of maintaining the health and strength of the bone by removing old bones and forming new bones. This cycle has the following four stages:

1 Activation phase: The pre-osteocytes are activated by granulocyte colony-stimulating factor and differentiate into mature osteoclasts under the influence of other cytokines and growth factors.

2 absorption stage: newly formed osteoclasts secrete acidic substances, dissolve and digest the matrix and minerals of old bone.

3 Reversal phase: When the cavity formed by the absorption reaches the expected depth, the absorption ends.

4 Osteogenic stage: Osteoblasts are attracted into the cavity formed by absorption, mature under the influence of growth factors and various hormones, and form new bone filling in the absorption cavity.

Bone balance: Under normal conditions, the absorption phase of the bone is maintained in equilibrium with the reconstituted phase, that is, the cavity left by the osteoclasts normally dissolves and absorbs the old bone, and the osteoid secreted by the osteoblasts is completely filled and further Mineralization, this process is the fundamental condition for ensuring the normal balance of bone mass. When the activity of osteoclasts is excessively enhanced, the dissolution and absorption of bones increase, resulting in an increase in the depth of the cavity after absorption. When the osteoblasts are damaged. It will improperly secrete osteoids in the normal absorption of the cavity. The accelerated bone loss in menopausal women is caused by the significant increase in osteoclast activity. The slow bone loss associated with age is due to osteoblast activity. Reduced, therefore, the former can reverse the pathological process of osteoporosis by applying anti-absorbent drugs, and the latter can use bone remodeling stimuli to reverse the low-speed bone loss associated with bone deficiency.

Bone mass regulation: Human bone mass increases naturally with age, reaching the maximum bone mineral mass in premenopausal adulthood, ie peak bone mass, peak bone mass is a milestone in human bone development, and it has at least two clinically The important function of the aspect is that the higher the peak bone mass, the lower the risk of osteoporosis. Therefore, it is necessary to encourage women to reach the peak bone mass before menopause, and the second is to compare the peak bone mass of the patient. The measured bone density contributes to the clinical estimation of the relative loss of bone density in patients.

Bone loss is part of the inevitable normal aging process in humans. The peak bone mass of vertebrae is generally achieved in the second decade of humans. Because of the higher metabolic rate and surface area of trabecular bone than cortical bone, trabecular bone Bone loss is more significant than bone loss in cortical bone. The rate of cortical bone loss is different at different ages, such as from 40 years old to menopause, 0.3% to 0.5% per year, 1 to 8 years after menopause, 2% to 3% per year. The trabecular bone loss has been around since the age of 30 and is about 1.2% lost each year.

Osteoporosis prevention in the elderly

Women before and after menopause, the bone mass is relatively low, we must strive to prevent excessive loss of bone mass as much as possible, the more effective prevention and treatment method is to use estrogen, intake of sufficient calcium, 1000 ~ 1500mg / d calcium. Inhibit bone absorption and reduce bone loss

Osteoporosis complications in the elderly Complications

The most common complications of osteoporosis are mainly

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 in the elderly Common symptoms Osteoporosis, bone pain, diffuse osteoporosis, chest tightness, fatigue, humpback, vitamin C, lack of back pain, thoracolumbar vertebral compression fracture, vitamin D deficiency

Clinical types can be divided into primary and secondary categories according to the cause:

1. Primary osteoporosis

Primary osteoporosis refers to systemic bone changes with a decrease in bone mass per unit volume and degeneration of bone tissue, including postmenopausal osteoporosis and senile osteoporosis, which are more common in the past. Primary osteoporosis can be divided into two subtypes.

Type I osteoporosis: also known as postmenopausal osteoporosis, the age of onset is mostly after menopause to 70 years old, mainly found in women, female: male is 6:1, osteoporosis is mainly osteoporosis, most Common fracture sites are more common in vertebral bodies and distal humerus. The main pathogenic factor is estrogen deficiency.

Type II osteoporosis: also known as senile osteoporosis, the age of onset is more than 70 years old, women are slightly more than men, female: male is 2:1, cancellous bone and cortical bone are also loose, fracture site More common in the femur, vertebrae and ulna and ulna, the main pathogenesis is ageing.

2. Secondary osteoporosis

Refers to the secondary cause of a clear primary disease or osteoporosis, the main causes are as follows:

(1) Endocrine diseases:

1 Adrenal cortical disease: Cushing's disease, Addison's disease.

2 gonad diseases: gonadotropin hyperplasia, abnormal menopausal osteoporosis, hypogonadism.

3 pituitary disease: acromegaly, hypopituitarism.

4 thyroid disease: hypothyroidism, hyperthyroidism.

5 parathyroid disease: hyperparathyroidism.

6 pancreatic disease: diabetes.

(2) Bone marrow disease: bone marrow disease, leukemia, lymphatic disease, metastases, high-break disease, anemia (sickle cells, thalassemia, hemophilia), mast cell disease.

(3) Kidney disease: renal failure, renal insufficiency, renal tubular acidosis, renal osteodystrophy.

(4) Rheumatic diseases: rheumatoid arthritis, ankylosing spondylitis, chronic inflammatory polyarthrosis.

(5) Gastrointestinal diseases: Gastrointestinal malabsorption syndrome, gastrectomy, intestinal bypass, etc.

(6) Liver disease: cirrhosis (primary biliary or idiopathic).

(7) Congenital connective tissue disease: osteoblast deficiency, homocystinuria, Ehlers-Danos syndrome and Marfan syndrome.

(8) Drug factors: steroids, heparin, anticonvulsants, immunosuppressants, thyroid preparations, antacids (aluminum preparations).

(9) Nutritional factors: vitamin C deficiency, vitamin D deficiency, excessive vitamin AD, calcium deficiency, protein deficiency.

(10) Disuse factors: limb paralysis caused by prolonged bed rest, weight loss caused by space flight, after fracture.

3. Idiopathic osteoporosis

(1) Adolescent osteoporosis.

(2) Young adults, adult osteoporosis.

(3) Women's pregnancy, lactation osteoporosis.

Primary osteoporosis can be divided into 2 types, type I is high conversion osteoporosis, that is, bone resorption and bone formation are active, but mainly bone resorption, common in postmenopausal osteoporosis, type II For low-transformation osteoporosis, that is, bone resorption and bone formation are not active, but still mainly bone resorption, common in senile osteoporosis.

Osteoporosis is not difficult to diagnose by medical history, clinical manifestations, bone mineral density measurement, and bone resorption bone formation.

In postmenopausal women or the elderly, there is a risk of osteoporosis, such as old age, ethnic inheritance, lifestyle habits, exercise reduction, smoking, drinking, long-term intake of coffee, etc., clinical manifestations of osteoporosis and osteoporosis The degree is related to the fracture. In the early stage, the osteoporosis is mild, and there is often no obvious discomfort. It is called quiet disease. However, in the middle and late stage, local or whole body bone pain occurs, and the height becomes short and hunched. There are external forces or slight external forces that are fractures and even breathing disorders.

Examination of osteoporosis in the elderly

Bone formation index

(1) Serum bone-derived alkaline phosphatase (bALP): This enzyme is synthesized and secreted by osteoblasts. Its concentration in the blood can reflect the level of osteoblasts. The monitoring and dynamic observation of bALP activity will be the disease. Early diagnosis, monitoring of treatment effects, and prognosis of the disease provide an effective basis.

(2) Osteocalcin (BGP): Osteocalcin, also known as osteocalcin, is derived from non-gelatin of osteoblasts with a half-life of 5 min. Monitoring blood BGP not only reflects osteoblast activity but also helps to observe drugs. Osteoblasts are treated after treatment. When bone formation is coupled with bone resorption, osteocalcin is a specific indicator of bone formation. In many endocrine diseases and bone diseases, serum osteocalcin changes, which is clinically diagnosed. An important biochemical indicator for detecting the condition can directly reflect the rate of bone formation. Anti-bone resorption drugs can reduce BGP levels, while stimulating bone formation treatment increases BGP levels.

(3) Procollagen elongation peptide (PICP): This peptide is a polypeptide excreted in the process of type I collagen modification, and its level can reflect the collagen synthesis function of osteoblasts.

2. Bone resorption index

(1) fasting urinary calcium / creatinine ratio: normal value is 0.13 ± 0.01, such as increased urinary calcium excretion, indicating increased bone resorption rate, bone resorption, bone calcium released into the blood, leading to elevated urinary calcium, due to affecting urinary calcium There are many factors, so the specificity is not strong.

(2) Fasting urinary hydroxyproline/creatinine ratio: The normal high limit is 0.016, and the ratio is increased, indicating that the bone resorption rate is increased. Although it is more commonly used, the specificity and sensitivity are not strong.

(3) Tartrate-resistant acid phosphatase (TRAP): mainly present in osteoclasts, its level can reflect bone resorption, serum TRAP is significantly increased in postmenopausal women, hyperparathyroidism and hyperthyroidism, and estrogen replacement therapy is adopted in postmenopausal women. After that, serum TRAP decreased by 70%, which is a good indicator of osteoclast activity.

(4) Type I collagen pyridine cross-linking compound and terminal peptide: as a bone resorption index, attention has been paid in recent years, and it has strong specificity and representativeness.

Bone turnover markers excrete circadian rhythms, which suggests that we need to standardize when collecting specimens.

3. Bone density determination method

Single photon absorption (SPA), two-photon absorption (DPA), quantitative CT (QCT), quantitative ultrasound (QUS), dual-energy X-ray absorptiometry (DEXA), etc., to determine osteoporosis Degree, determine the diagnosis and check the effect of drug treatment, which is better with dual-energy X-ray absorptiometry, is currently recognized as the gold standard for osteoporosis examination, compared with QCT, has low price, the exact sensitivity and correct result The advantage of high averageness was the development of two-photon technology in the 1970s, where two different energy rays were used to calibrate different soft tissue thicknesses and fat content. Two-photons were quickly replaced by dual-energy X-rays and were widely used. The two work the same way, but DXA is faster, more accurate and more accurate than DPA scanning. It avoids the isotope attenuation. Its principle is that the two energy X-rays pass through the body at the same time and are received by the detector due to different tissues ( Mainly bone, fat and muscle) have different responses to the high and low energy X-rays, so they can be corrected by mathematical formulas. Different manufacturers use different techniques to obtain two energy X-rays, one is K-edge filtering, and the other is K-edge filtering. Using a switch.

4. Clinical application

(1) Diagnosis of osteoporosis: There are a variety of measurement methods available for diagnosing bone density reduction. When selecting measurement methods and sites, there are two issues to consider: bone density of bones in various parts of the body is inconsistent, bone in some parts The density can be falsely increased, and the bone density of bones in each part is not uniform. The relative bone density of each spine, hip and wrist is different. This inconsistency is more obvious in the early postmenopausal than in older women, possibly after menopause. The conversion rate and bone loss rate of early cancellous bone are higher than that of older women. Because of this, in early postmenopausal women, the proportion of osteoporosis measured by DXA or QCT in the waist and bone density is better than the measurement of the wrist or hip. High, in order to avoid missed diagnosis, the ideal should be to measure more than one part.

After the age of 65, the inconsistency of bone density is weakened, and osteoporosis can be diagnosed according to the bone density of the hip or limbs, because the lumbar degeneration in the elderly is very common, and the osteophytes caused by degeneration can cause bone sclerosis. The secret holiday is rising.

(2) Predicting fractures: When determining appropriate measurement methods and interpreting bone mineral density results, the patient's age should be taken into consideration. Most bone mineral density predictions of fracture risk are concentrated in women over 65 years of age. In the menopausal population, therefore, the relative fracture risk of a 70-year-old woman at a certain bone density value cannot be cited in a 50-year-old woman, and age itself is an independent risk factor for predicting fracture.

(3) Monitoring changes in bone density over time: Bone density measurements can be used to monitor bone aging.

The possible variation in bone mineral density for each specific bone site should be taken into account. For example, the bone density of the femoral neck naturally changes to a precision of 2.0% per year for 1% femoral neck bone density measurement. This requires observation for 6 years to be found at 95. The 6.0% change in the % confidence interval differs in the condition of the spine. Generally, the rate of change of bone density in the lumbar spine after menopause or drug treatment can reach 3%, and the measurement error is often 1%, so it is appropriate to measure once a year. It is necessary to know in advance the magnitude of the change in physiological bone density at each specific bone site and the error in the measurement of bone density at that location in order to reasonably explain that the change in continuous bone density measurement is a true change, not a measurement error.

5. Indications for bone density measurement techniques

(1) Assessment of menopausal women: Whether menopausal women need estrogen therapy depends on many factors, including current bone mineral density values, menopausal symptom severity, patient and physician choices, laboratory tests showing rapid bone loss and cardiovascular disease Long-term risk, the absolute value of women's bone mineral density during menopause and the extent of subsequent bone loss are important factors in assessing the risk of fracture. It is possible to determine whether estrogen therapy is needed according to bone density, and bone density measurement can further provide females. Information on the effects of hormone therapy.

(2) Osteoporosis and severity: bone mineral density should be examined when osteoporosis or X-ray plain film is suspected to be a non-traumatic fracture (ie, osteoporotic fracture). Recent studies have shown that the absolute value of MBD is a fracture risk. The predictor of BMD is closely related to bone strength, BMD is reduced, bone strength is weakened, and fracture risk is increased. Therefore, BMD itself is a major indicator of the risk of osteoporosis and an important basis for deciding whether to treat.

(3) Evaluation of patients with metabolic bone disease: Many metabolic bone diseases, such as hyperparathyroidism, Cushing syndrome and chronic cortisone treatment, which seriously affect the metabolism of calcium, can affect bones, and other common bones The disease has androgen deficiency, nutrition related diseases, thyroxine treatment, alcoholism, disuse, anticoagulation, renal osteopathy, etc. For these secondary osteoporosis, bone mineral density measurement is very important because BMD measurement can be reflected The extent of the disease and the condition of the treatment.

(4) Observing the efficacy and assessing the disease process: If there is no effective treatment in the clinic and can reduce the risk of fracture, then measuring BMD is of little significance. There are many studies on the effects of various treatments on bone mineral density, but There are few studies on the risk of fractures. Prospective, randomized clinical trials have shown that many drugs can increase bone density and reduce fractures, such as bisphosphonates, PTH, SERMS, etc. Currently, most clinical trials of DXA bone mineral density are final. Observed values, and rarely used fractures as the final observation. It should be noted here that if bone tissue is normal, bone density is closely related to bone strength, that is, bone density can be used as an indicator of bone strength, but there are also disjointed In the case of skeletal fluorosis and osteopetrosis, the bone density is increased, but the bone strength is reduced, because the quality of the bone tissue itself changes, so the increase in bone density after drug treatment does not necessarily mean an increase in bone strength, nor Represents a reduction in the incidence of fractures. In addition, these clinical trials and epidemiological investigations are all population studies with low bone density. Fold risk, drug treatment can increase bone density, while the individual is concerned, the ability to predict the risk of bone fracture weak.

The neglected side of osteoporosis research should be noted. The clinical consequences of osteoporosis are osteoporotic fractures, which often occur in the spine, femoral neck and wrist. The occurrence of fracture is a very complicated process. Intensity is only one of the factors, and may be a secondary factor compared to the impact of the fall, especially the femoral neck and wrist fractures. The impact of the fall may be the main cause of the fracture.

Fall is a factor that cannot be predicted and is difficult to quantify. Studies have shown that femoral neck fractures are closely related to the vision of the elderly and the general health of the body. Therefore, improving the vision and general health of the elderly can reduce the incidence of fractures. The hip protector from Safehip, Denmark, adds a high-strength protective pad to the greater trochanter of the femur in the panties. Studies have shown that hip protectors can reduce the incidence of femoral neck fractures (Lauritzen, 1996). Aspects are also worth studying.

6. Measurement site

(1) vertebral body: the most commonly selected examination site, mainly using dual-energy X-ray absorptiometry, generally selected chest 12 ~ lumbar 4 vertebrae density detection is the main method for early detection of osteoporosis in women, before the age of 70 The lumbar lateral position of elderly women is a sensitive part for the diagnosis of osteoporosis. Pay attention to the following points when measuring the bone density of lumbar vertebrae:

1 Compare the bone mineral density of the patient's waist 2 and waist 4 with the bone mineral density of the same part of a 30-year-old adult or a normal-aged normal.

2 pay attention to the lowest bone density of waist 1 ~ waist 4.

3 patients with moderate to severe bone deficiency must expand the scope of measurement, from chest 4 to waist 5.

(2) distal humerus and ulna: the main use of SPA or DPA, the current use of peripheral dual-energy X-ray absorptiometry, the determination of bone mineral density in the distal radius for the diagnosis of senile osteoporosis or general osteoporosis However, the early diagnosis of postmenopausal osteoporosis has a greater limitation. Moreover, the peripheral bone density measurement can not determine the most obvious site of osteoporosis, but the sacral and ulnar bones are compared and the distal humerus osteoporosis is found. The change in bone density at the time of the disease is more pronounced and more sensitive than the ulna.

(3) Femur: It is a commonly used bone density measurement site, including the femoral neck, Wards triangle and rotor. It is commonly measured by dual energy X-ray absorptiometry. The femoral neck is mainly cortical bone, and the Wards triangle has both cortical bone and Cancellous bone, but mainly cancellous bone, the bone density change in this part has a good correlation with the lumbar spine and distal radius. The large sample cross-sectional study found that the Wards triangle was 15 years before menopause. At the age of 35 and 10 years (about 40 years old), bone loss begins, and by the time of menopause (about 50 years old), it has lost 11%.

7. Analysis of results

Judgment of bone density determination results: There are two criteria for judging osteoporosis from bone mineral density, and the two standards are usually used in combination.

(1) T-score: According to the World Health Organization recommended standard deviation below the peak bone mass to determine osteoporosis, lower than the peak bone mass (bone density at 30 years old) 1 to 2.5 standard deviation, for the bone Lack of quality, less than 2.5 standard deviations for osteoporosis, less than 2.5 standard deviations, accompanied by fractures for confirmed osteoporosis, in general, bone density reduced to 80% to 90% of peak bone mass %, for mild osteoporosis (or osteopenia), bone density decreased to 60% to 80% of the peak bone mass, moderate osteoporosis, bone density decreased to less than 60% of the peak amount, then Significant osteoporosis.

(2) Z-score: It is based on the standard deviation of bone mineral density of normal people of the same age to determine osteoporosis, which is less than 1 standard deviation of the normal density of the same age, and is osteoporosis.

8. Bone X-ray examination

X-ray photograph is a more basic examination of osteoporosis, but it is not sensitive. It usually changes more than 30% of bone density. It can show a decrease in bone density, thinning of cortex, expansion of Harvard tube, trabecular bone. The gap is widened, the transverse trabecular bone disappears, and the bone structure is uniform and uniform. Although the conventional X-ray is not helpful in the diagnosis of osteoporosis, especially in early diagnosis, in the diagnosis of the cause of osteoporosis, it is found that the clinical symptoms are not typical. Vertebral fractures and the identification of other bone diseases are still essential, such as the subperiosteal bone resorption that is characteristic of hyperparathyroidism, and the linear translucent area during bone softening.

In addition, with reference to spine X-ray comminuted fractures, osteophytes, soft tissue calcification, vertebral biconcave deformation, chest 11, 12 vertebral body, lumbar 1, 2 vertebral body often have compression fractures, etc., to correctly explain bone density measurement The measured high bone density state is of great value, so physicians should be familiar with the performance of conventional X-rays of osteoporosis.

9. High resolution CT

Bone mass or bone density measurement alone can provide important information about the risk of osteoporotic fractures, but many studies have shown that bone mineral measurements can only partially explain bone strength, although osteoporosis patients have reduced bone mass and bone density, but normal There is still a lot of overlap between healthy people. In addition, bone loss is a risk factor for fracture. However, the increase in bone mass in patients with osteoporosis is not necessarily protective. Many studies have shown that quantitative determination of bone structure characteristics can help improve assessment. The ability of bone strength.

Microscopic computed tomography (CT) and magnetic resonance imaging, these imaging techniques can detect bone structure.

High-resolution CT uses relatively high-resolution and thin-layer scanning to clearly show the structural features of the vertebrae and hip joints, showing the trabecular bone structure at the distal end of the humerus, which can be used to measure the bone mineral density of cortical bone and cancellous bone, respectively. Trabecular structure.

10.Quantitative magnetic resonance

Magnetic resonance technology is complicated and rapid development. Although the bone tissue itself does not contain protons, the soft tissue and bone marrow around the bone tissue contain a lot of fat and water protons, which can produce strong signals, so the trabecular bone and cortical bone structure are clearly drawn. It can be expressed as bone marrow edema, T1 weighted images show low signal intensity, and T2-weighted images show high signal intensity. This bone marrow edema can disappear after several months.

11. Radionuclide scanning

It is characterized by high uptake of radionuclides, but the specificity is poor and cannot be qualitatively diagnosed.

Diagnosis and diagnosis of osteoporosis in the elderly

Diagnostic criteria

Bone pain

Bone pain is the most common and most important symptom of osteoporosis. The main reasons are 3 points:

1 bone turnover is too fast, increased bone resorption leads to trabecular bone absorption, fracture, cortical bone thinning, perforation, resulting in systemic pain.

2 Under the action of stress, the bone is deformed due to the significant decrease in bone strength, resulting in pain caused by wedge deformation or fishtail deformation.

3 Due to bone deformation, the muscle tension attached to the bone changes, the muscle is prone to fatigue, and sputum occurs, resulting in sarcolemma pain. The most common areas of pain are the lower back, ribs and ankles, and the chest and back are severely deformed. There are pains everywhere.

2. Shortened length, hunchback

Among the bones composed of cancellous bone and cortical bone, cancellous bone is more prone to osteoporosis. The vertebral body is mainly composed of cancellous bone, and supports the whole body, which is prone to symptoms such as height and shortness.

The average height of the vertebral body is about 2cm. When the osteoporosis is broken, the trabecular bone is destroyed, the number is reduced, the intensity is weakened, and the vertebral body is easily deformed. In the case of severe osteoporosis, the entire spine can be shortened by about 10-15 cm. The study found that women are After the age of 60, men gradually appear to have a shorter height after the age of 65. Women are shortened by about 4 cm at the age of 65, and shortened by about 9 cm at the age of 75. The vertebral body is compressed, but the posterior structures such as spinous processes, lamina, and pedicles are not compressed. , resulting in the entire spine flexion and posterior kyphosis deformity, the heavier the hunchback, the symptoms of low back pain are also obvious, due to the force, some patients are also accompanied by scoliosis.

3. Fracture

Studies have confirmed that the fracture risk increases by 1.5-2.5 times for every 0.1g/cm2 of bone density reduction (or 2SD below the peak bone mass), and the occurrence time is more than 5-8 years after menopause. The main symptom of fracture is pain. The lighter often has no obvious feeling, and the severe compression fracture is immediately painful, and gradually relieves after about 3 to 4 weeks, and the hunchback is left behind, and the height is lowered.

Primary osteoporosis occurs first in the cancellous bone region, resulting in trabecular bone absorption, fracture, and decreased number. At the same time, perforation occurs in the cortical bone region, and the cortex becomes thin, resulting in osteoporotic fractures that are prone to enrichment. Thoracic and lumbar vertebrae of the cancellous bone, hip, distal humerus and metaphyseal end of long tubular bone, common thoracolumbar vertebral compression fracture, femoral neck and intertrochanteric fracture, Colles fracture, humeral neck, supracondylar fracture of the humerus, ankle fracture The fracture of the tibial plateau, the supracondylar fracture of the femur, etc., the characteristics of osteoporotic fracture: it can occur under the action of slight external force such as twisting the body, holding objects, opening windows, indoor daily activities, falling.

4. Respiratory disorders

Respiratory disorders caused by osteoporosis are mainly caused by spinal deformity and thoracic deformity. Although patients have chest tightness, shortness of breath, difficulty in breathing and cyanosis, pulmonary function measurement can find lung capacity and maximum ventilation. cut back.

Differential diagnosis

Osteomalacia

Blood calcium levels are lower or lower, serum phosphorus is reduced to varying degrees, renal osteopathy, blood urea nitrogen and creatinine can reflect the condition, blood phosphorus can be elevated, blood calcium is low, blood phosphatase is low, ALD is elevated, And other blood and urine biochemical tests.

2. Hyperparathyroidism

Increased blood calcium, decreased blood phosphorus, elevated ALP, bone scan, hand, skull X-ray can show special types, magnetic resonance imaging shows increased parathyroid glands, and other biochemical tests.

3. Myeloma

Blood group examination has cell anemia, erythrocyte sedimentation rate can be increased to more than 100mm / h, serum immunoelectrophoresis 90% abnormal IGG and IGA, serum calcium increased, bone marrow puncture may be more than 20% plasma cells, osteoporosis patients generally hematuria examination Normal, other secondary osteoporosis has other biochemical abnormal changes corresponding to other diseases, such as diabetic osteoporosis can increase blood sugar, hyperthyroidism can increase T3, T4.

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