At establishment of the diagnosis "Osteoporosis" is considered by features of clinical manifestations, results of an assessment of laboratory studying of characteristics of a bone and mineral exchange, and also these measurements of mineral density of a bone.
Clinical displays of osteoporosis
In spite of the fact that osteoporosis at children and teenagers a long time proceeds latentno, at the subclinical level, to pediatricians, especially district, family doctors, it is necessary to pay attention during the collecting the anamnesis and inspection of the child to a number of the moments. In view of that osteoporosis and osteosinging at children's age develop in a backbone, proximal department of femoral and humeral bones, distal departments of beam bones more often, dorsodynias, in legs can be the early, "guarding" symptoms of a disease, is more rare — in hands. Pains arise at certain provisions of a body, the movements, to an exercise stress are characterized as aching. At the same time complaints of patients to fast fatigue in a standing position are frequent or "sitting". Starting inspection of the child, it is necessary to measure and estimate the actual growth indicators (possibly growth reduction), to pay attention to features of a bearing, such as "a roundish back", a kyphoscoliosis, a lordosis in lumbar department, to carry out a scrupulous palpation of a backbone. Besides, at the child protrusion of a stomach, existence of skin folds on lateral surfaces of a trunk are possible.
One of pathognomonic clinical criteria of diagnosis of osteoporosis is emergence of a change, especially — the incident at a so-called minimum injury. At the same time the change is defined as occurred spontaneously, at the sharp movement or in case of falling from height which is not exceeding own growth, etc. In a similar situation sharp pain in the place of a change, external signs of deformation of a bone, restriction of functional capacity appear, especially at damage of distal department of a beam bone and proximal department of a femur. In cases of fractures of the vertebras associated with osteoporosis along with a pain syndrome, reduction of growth of the child, increase in the sizes of a chest kyphosis, restriction of mobility, ability to self-service, etc. can be noted.
Emergence of the symptomatology described above is the direct indication for performance of a standard X-ray analysis of an affected area, definition of biochemical markers of osteoporosis — for the purpose of establishment of degree of manifestation of mineral density of a bone tissue.
Laboratory diagnosis of bone and mineral osteoporosis
Considering methods of an assessment of bone mineral density, still insufficiently available to wide layers of the children's population, (osteodensitometry), in recent years more and more attention is paid to biochemical markers which allow to define nature of metabolic shifts in a bone tissue, a condition of a mineral exchange, osteoporosis option, etc. At the same time all biochemical markers used for diagnosis of osteoporosis at children's age divide into 2 groups.
The first is made by the markers reflecting the main functions on maintenance of level of calcium in an organism (the kaltsiyreguliruyushchy, supporting mineral homeostasis, a renal reabsorption, absorption However it is necessary to remember that according to the roentgenogram it is visually possible to state osteoporosis only at late stages when loss of bone weight for 20-40% takes place. Therefore on the accuracy, objectivity of the reproduced results the standard X-ray analysis considerably concedes to modern methods of osteodensitometry.
Among modern methods of measurement of MT To use:
Two-power x-ray absorbtsiometriya (dualenedgy X-ray absorptiometry) — DXA or DEXA
Quantitative Computer Tomography (QCT).
It should be noted that the most wide recognition in diagnosis of osteoporosis was gained by the DXA method which is considered as "the gold standard" of measurement of mineral density. The method differs in a number of advantages before other methods of research. First of all, the DXA method is highly sensitive and specific, exact, the mineral density of a bone tissue both axial, and peripheral allows to measure, skeleton sites, it is characterized by the minimum exposure dose, speed of research. When scanning of the studied site of a skeleton determine, first, the area of the scanned surface (Area, cm2), secondly, the maintenance of a bone mineral (Naval Forces — Bone Mineral Content, d) with consecutive calculation of important clinical parameter — sizes of projective mineral bone density of BMD (Bone Mineral Density). At this BMD = Naval Forces/Area, g/cm2.
Further, as the mineral density of a bone is not identical in various departments of a skeleton, it is calculated according to special standard automatic programs of scanning of various, specific sites of department of a skeleton (lumbar area, distal department of bones of a forearm, hip neck, etc.) in two projections. The computer providing osteodensitometers accompanying research includes reference base, i.e. normal indicators taking into account age and a floor. There are similar programs and for performance of researches in pediatric practice which give the chance to define the mineral density of a bone tissue at children's age, since birth. The size of mineral density of a bone tissue received at the same time automatically is compared with average normative, taking into account a deviation of individual values from middle-aged norm at children of the corresponding gender and age (Z-criterion). The result is expressed as a percentage and in terms of a standard deviation (SD). At the deviation equal to from 1 to 2,5 SD, state to osteosinging, and at value more than 2,5 SD — diagnose osteoporosis. Cases of a combination of the size SD exceeding 2,5 with a change regard as a severe form of osteoporosis. Unfortunately, the insufficient number of axial densitometers defined wider use of less expensive ultrasonic devices for peripheral sites of a skeleton — bone ultrasonometers (KUS). Quantitative ultrasonic densitometry allows to estimate a wave condition through a bone (SOS-speed attenuation) and by results of broadband attenuation of ultrasound (broad-band ultrasound attenuation) — BUA. By means of this method measurement of bones of a peripheral skeleton of a phalanx of fingers, a front surface of a tibial bone, a forearm bone (where, generally there is a compact bone tissue) and a calcaneus (there are sites with tubular structure) is possible that is more informative. Then on devices by means of which measure a calcaneus visualization allows to establish automatically area of research and to estimate positioning at repeated measurement.
Despite a number of shortcomings (the objective mistakes when calculating depending on quality of acoustic contact, a condition of skin in the field of measurement, sensitivity to temperature, impossibility of standardization and from here — insufficient reproducibility of a method), a number of researchers consider a method rather objective and very perspective (lack of beam loading, research speed, big accuracy, etc.) in view of simplicity and usability of the quantitative ultrasonic densitometry (QUD). In this regard quantitative ultrasonic densitometry is considered as screening method which allows to reveal the children and teenagers predisposed to fractures of bones (risk group), to confirm the diagnosis of osteoporosis and to estimate efficiency of the carried-out therapy. In Russia the structurally functional condition of a bone tissue of children and teenagers by use of ultrasonic densitometry was studied. At the same time, on the basis of inspection of the considerable contingent (1729) healthy children and teenagers aged from 7 till 17 flyings, normative data with calculation of average values and a standard deviation (tab.) are obtained.
Allows to have an opportunity of use of a method of a quantitative computer tomography volume, but not plane characteristics of a bone, to separately estimate with high precision a condition of both cortical, and trabecular part of the studied bone site. At the same time, in view of rather big beam loading and high cost of similar research, use of a method of a quantitative computer tomography in pediatric practice is significantly limited.
Indicators of a structurally functional condition of a bone tissue at children and teenagers
Note: M — average values, SD - a standard deviation.