From Big Medical Encyclopedia

OSTEOPATHY NEPHROGENIC (grech, osteon bone + pathos suffering, disease; grech, nephros a kidney + gennao to give rise, make; synonym: nephrogenic osteodystrophy, uraemic, azotemic osteosinging) — the diffusion damage of a skeleton at a renal failure and tubulopatiya caused by frustration calcium - phosphorus exchange.

Rakhitopodobny changes of bones at the children and teenagers having diseases of kidneys for the first time were described by Loukas (R. Page of Lucas) in 1883. The essence of these changes became clear after Marriott and Haulend's researches (W. M of Marriott, J. Howland), to-rye in 1916 revealed a hypocalcemia, a retention of phosphate and the acidosis connected with it at uraemia. Later dystrophic damages of a skeleton at nek-ry forms of enzymopathies with the isolated canalicular insufficiency were described.

The etiology and a pathogeny

are the Main reasons for O. of N hron, a renal failure, and also the inborn and acquired tubulopatiya, including: an idiopathic hypercalcemia, an idiopathic hypercalcuria, passing canalicular acidosis of Laytvud, hron, canalicular acidosis of Butler — Albright, a hereditary osteodystrophy or Albright's pseudohypoparathyroidism, phosphate diabetes or vitamin - D-resistant rickets, de Tony's syndrome — Debra — Fanko-ni, an okulotserebrorenalny syndrome of Lowe, Abdergalden's cystinosis — Linyaka, oxarods, a glycogenosis to Awnless wheat, gepato the lentikulyarny degeneration, a hypophosphatasia and the nek-ry other seldom found diseases which are followed by insufficiency of function of tubules.

O.'s frequency of N at a renal failure (uraemic O. of N) depends on duration of uraemia, age of patients, physical activity, a diet and character to lay down. actions. So, at insufficient correction calcium - phosphorus exchange in the course of treatment of a hemodialysis O.'s signs of N come to light in the first three years practically at each patient.

Exchange of calcium and phosphorus at diseases of kidneys is broken even before development of an azotemia. In the beginning disturbance has tranzitorny character and is eliminated with intense activity of mechanisms of regulation, including epithelial bodies. At further deterioration in function of kidneys and falling of glomerular filtering to 30 ml in 1 min. these disturbances meet constantly and conduct N to O.

The negative balance of calcium with reduction of the general and ionized calcium of blood is the main reason of O. of N that depends on low intestinal absorption and the increased elimination of calcium with excrements and urine. Digestion of calcium in intestines is interfered by excessive sedimentation by its phosphate and deficit of a kaltsiysvyazyvayushchy protein in a mucous membrane of duodenal and lean guts. Synthesis of a kaltsiysvyazyvayushchy protein is controlled by the activated vitamin D (see. Calciferols ). Activation of vitamin D at a renal failure is broken owing to inability of the affected kidneys to synthesize 1,25 dihydroxyvitamin D in enough.

In pathogeny The lake of N is important also positive balance of phosphorus. At reduced renal clearance phosphates collect in blood (see. Fosfatemiya ), what aggravates a hypocalcemia and acidosis (see).

Hypocalcemias, hyperphosphatemias and acidosis stimulate secretion parathormone (see) that shall promote recovery of the broken homeostasis since parathormone in healthy kidneys strengthens a canalicular reabsorption of calcium and brakes a reabsorption of phosphate. The most part of parathormone at the same time is inactivated by kidneys. At a renal failure the canalicular mechanism is weakened and is not able to recover a homeostasis. Besides, parathormone contributes to normalization of calcium of blood (see. Calcium ), stimulating a resorption of a bone tissue. However in connection with relative resistance of a bone tissue to parathormone calcium of blood at a renal failure remains reduced and only in case of much the expressed hyperfunction of epithelial bodies can reach or exceed datum level. Removal of phosphate kidneys significantly does not change. Since together with calcium from bones phosphate will be mobilized, the level of the last under the influence of parathormone increases in blood. The inactivation of parathormone patholologically is broken by the changed kidneys. Over time the condition of a secondary (regulatory) hyperparathyreosis develops, there is a hyperplasia and a hypertrophy of epithelial bodies.

The absorption of calcium caused by deficit of vitamin D leads gradually to demineralization of a skeleton and osteomalacy (see). Mechanical strength of bones decreases, bones are deformed, easily break, at children growth stops. Under the influence of parathormone osteoklas-tichesky and osteoblastic reactions and as the result of it accelerates reorganization of bone structures become more active what high activity of an alkaline phosphatase in blood and the increased release of oxyproline with urine testifies to. At the same time there is an accumulation of preferential unripe, not mineralized osteoid. The mass of bones is a little increased, their density is reduced. As a result of unequal sensitivity to parathormone of bones of a skeleton there are centers of a subperiosteal and endosteal resorption, an acro-osteolysis, zones of reorganization (see. Loozera of a zone ) and changes. Rather seldom at O. the N develops osteosclerosis (see), shown consolidation of structure of bones of a calvaria, switching plates of bodies of vertebrae and diaphysis of large tubular bones. The N is among O.'s manifestations osteoporosis (see), arising, apparently, only as a result of proteinaceous starvation, a hypokinesia, a stress, therapy by glucocorticoids concerning a basic disease, and in some cases — after transplantation of a kidney to the patient, at to-rogo owing to constant reception of high doses of glucocorticoids exchange of vitamin D and digestion of calcium are broken. Dystrophic changes of a skeleton at the same time are characterized by serious consequences in the form of aseptic osteonecrosis (see), the hip striking a head, a shoulder, the acromial end of a clavicle, a shovel. The progressing O.'s current of N after transplantation of kidneys can be connected with adenoma of the epithelial body which developed as a result of its hyperplasia at long uraemia.

Demineralization of a skeleton and oversaturation of an organism phosphate in combination with acidosis contribute to ectopic calcification, i.e. adjournment of salts in soft tissues (see. Calcification ). Defeat has generalized character, however changes come to light in the fabrics rich with collagen earlier.

The most important pathogenetic factors of O. of N at tubulopatiya are the metabolic acidosis caused by an insufficient reabsorption of a hydrocarbonate, an insufficient ammoniogenesis, accumulation formed a lot of milk and pyroracemic to - t; patol, the calciuria which is quite often depending on acidosis; an excess fosfaturiya with a hypophosphatemia or without it; secondary hyperparathyreosis; a secretory or receptor hypoparathyrosis at relative surplus of a ti-rokaltsitonin; the perverted sensitivity to vitamin D; excess binding of calcium in slightly soluble salt out of a bone tissue; inability of a bone tissue to a full-fledged mineralization owing to deficit of an alkaline phosphatase and leak of phosphate with urine. O.'s pathogeny of N at this or that form of a tubulopatiya can be caused by one of these factors or their combination.

Pathological anatomy

Any changes in any link of a complex system of a kidney — closed glands — bones lead to changes of function and structure of two other links of this system. Therefore, the main localization of pathoanatomical changes at O. of N are kidneys, epithelial bodies and bones.

Changes of epithelial bodies have no specifics. A. V. Rusakov pointed to their considerable hypertrophy at hron, a renal failure of any etiology. Changes in kidneys are characterized by the basic patol, the process which led N to O.

At a research of a bone tissue of the adults who died at a picture of uraemia on the soil hron, a glomerulonephritis, hron, pyelonephritis and a polycystosis of kidneys A. V. Rusakov found signs of substantial increase of intra bone metabolism. At the same time external shape of bones not always undergoes essential changes. Microscopically find strengthening of a resorption of a bone tissue in combination with a hyperplasia of endosteal elements, however with very poorly expressed new growth of a bone.

At hron, A. V. Rusakov allocated to a renal failure of the same etiology at adults two types of intra bone changes: osteosclerotic and osteomalacic. The osteosclerotic type is characterized by the strengthened osteoklastichesky resorption of correctly created mature splenial and a powerful new growth of the bone substance consisting in the beginning of an unripe fibrous bone. In the subsequent fibrous substance is exposed to the strengthened calcification with formation of the osteonny structures inherent to a splenial. Excess growth of an endosteum leads to almost full substitution of marrowy spaces cellular and fibrous fabric with replacement of the hemopoietic fabric. Traces of repeated reorganizations of bone substance are morphologically shown by existence of a large number of the so-called detrital structures divided by lines of pasting and having an appearance of the remains of the osteons which underwent a rassasyvaniye. The osteosclerotic type O. of N on the microscopic picture has much in common with a parathyroid form of an osteodystrophy.

The osteomalacic type O. of N is characterized by the fact that against the background of an active resorption of bone substance there is a new growth low-cellular neobyzvestvlyayushchey-sya ossiform fabric. Processes of reorganization in different bones of a skeleton can develop various rates and have nek-ry high-quality coloring. So, at far come process A. V. Rusakov described the simple atrophy with a rarefikation of a compact layer of long tubular bones caused by the raised resorption and a weak new growth of a bone whereas in spongy bones excess formation of not calciphied ossiform fabric is noted. At the same time bones of a backbone, edges, a basin, an epiphysis of tubular bones are easily knifed, and a diaphysis of tubular bones excessively brittle that quite often leads to their changes.

Nephrogenic osteomalacy is morphologically similar to osteomalacy at D-avitaminosis. The question of why in one cases at O. of N the osteosclerosis develops, and in others osteomalacy, remains open. Degree of manifestation of intra bone changes at O. of N at adults completely depends on duration of a disease of kidneys.

The clinical picture

Clinically O. of N at hron, a renal failure is shown rather late when changes of a skeleton happen already sufficiently expressed. A constant symptom is weakness of muscles of a back, a shoulder and pelvic girdle, especially at rise on a ladder or a rising from a bed. Muscular weakness caused the shaking (duck) gait arising at nek-ry sick O. of N. Dull aches in bones are characteristic, it is more at night and during the change of weather. They have constant character and are hard transferred by patients. Pains preferential in bones of forearms, shins, feet, in edges and a backbone are localized. At a palpation of a bone are slightly painful. Because of a compression of bodies of vertebrae reduction of growth is possible, can develop kyphosis (see) and deformation of a thorax. Suddenly, without rather serious reason there are fractures of edges or some other bones which are followed characteristic a wedge, a picture (see. Changes ). The separation of a sinew in the place of its attachment to a bone is possible.

Calcification of periartikulyarny fabrics and sheaves disfigures joints. Periodically there are arthritises which are followed by a hyperemia and hypostasis of fabrics, temperature increase in joints (sometimes and the general body temperature), a bursitis, a tendovaginitis, and also costal perichondrites with consensual pleurisy. Clinical manifestations of calcification of skin, vessels, eyes, parenchymatous bodies are characteristic.

The lake of N at tubulopatiya at teenagers and adults — de Tony's syndrome — Debra — Fankoni (see. De Tony — Debra — Fankoni a syndrome ), Butler's syndrome — Albright (see. Laytvuda — Albright a syndrome ), phosphate diabetes (see) — clinically a little in what the N at a chronic renal failure differs from O. The prevalence of osteomalacy with deformation and patol, fractures of bones attracts attention a nek-swarm at less expressed phenomena of ectopic calcification of periartikulyarny fabrics. Calcification of arteries at the same time happens rather expressed.

O.'s current of N progressing. Dialysis and other methods of extrarenal clarification of blood, without curing O. of N, constrain its development.

The diagnosis

uraemic O.'s Diagnosis N is based on early detection of a renal failure. At the same time recognize situation that in all cases of an azotemia (creatinine of blood is higher than 2 mg / 100 ml) absorption of calcium is broken and its content in blood is reduced. Therefore, the normal or increased level of calcium of blood at an azotemia gives the grounds to assume existence of a secondary hyperparathyreosis and inherent O. of N of changes of bones. Also the hyperphosphatemia, resistant deficit of the bases, high activity of a bone isoenzyme of an alkaline phosphatase, the increased release of oxyproline with urine, substantial increase of content of parathormone in blood are characteristic of this form O. of N.

O.'s diagnosis N at tubulopatiya at teenagers and adults is based on laboratory definition of nature of tubular dysfunction (disturbance of processes of concoction, a polyuria, an amino-aciduria, leakage of a hydrocarbonate, a glucosuria, etc.), comparison of the received results to extrarenal displays of a disease and data of a X-ray radiological research of a skeleton.

The X-ray pattern of a skeleton at O. of N is defined by duration of a disease, age of patients and duration of treatment by means of dialysis. Frequency rentgenol. identifications of signs of O. of N depends also on a technique of a research. The roentgenograms of bones made on a fine-grained film without X-ray intensifying screens give images of higher quality that allows to consider them at increase and to find changes of ossicles, invisible at a usual method.

Fig. 1. The roentgenogram of an average phalanx of the II finger of a hand at a chronic renal failure: a sub-periosteal resorption in the form of roundish defects of a cortical layer of a bone (are specified by shooters) and consolidation of a periosteum.
Fig. 2. The roentgenogram of plusnevy bones of foot at a chronic renal failure: shooters specified a razvolokneniye of a cortical layer of a bone (is increased).

The most often found sign of a secondary hyperparathyreosis at O. of N is the subperiosteal resorption (fig. 1). It appears in phalanxes and other bones, but phalanxes give thinner image of structure. More often the resorption arises on the radial surface of average phalanxes. The bast layer of bones seems to razvo-loknenny (fig. 2). Sometimes at O. the N can find cystous changes of bones (brown tumors). A subperiosteum the lny resorption, a razvolokneniye of a bast layer and formation of cysts, except phalanxes, are observed in edges, pelvic bones, clavicles, bones of a mandible, femurs, a skull. At O. of N the picture of a calvaria is peculiar, to-ry has an appearance of «ground glass», at more expressed resorption the image of bones of a skull has a granular appearance with larger centers, at the same time there can be sites of more dense bone.

Fig. 3. The roentgenogram of a basin of the patient with a chronic renal failure: sharp osteoporosis and formation of the centers, (are specified by shooters) pathological functional reorganization in pelvic bones.
by Fig. 4. The roentgenogram of the right hip joint of the patient with a chronic renal failure (an aseptic necrosis of a head of a femur): the head of a femur is deformed; shooters specified sites of an osteonecrosis of a bone

Increase in quantity and thickness of bone trabeculas at O. the N causes a X-ray pattern of an osteosclerosis. Pyuezhle of all it is observed in bodies of vertebrae where dense strips alternate with more transparent. The osteosclerosis can be noted also in edges, a skull and tubular bones. One of radiological manifestations of osteomalacy are zones of reorganization of a bone tissue (Loozer's zone). In a picture they are visible as the ghost lines, perpendicular to a bast layer, reminding a change. Zones of reorganization can be found in a clavicle, pelvic bones (fig. 3) and long tubular bones. Osteomalacy can lead to deformation of an acetabular hollow. At some patients, long time treated a hemodialysis, decreases the mass of a bone tissue and fractures develop. The secondary hyperparathyreosis can give a picture of a fibrous osteit with focal consolidation of a bone. Along with a resorption of a bone there is a formation of a new bone. It is observed mainly at patients, is long treated a hemodialysis. Periosteal formation of a new bone has an appearance of the lamina separated from a periosteum. At patients is after renal transplantation and it is long treated a hemodialysis the osteonecrosis (fig. 4) can be observed. Degree of a mineralization of bones can be defined is intravital by method X-ray densitometries (see).

Stsintigrafiya (see) bones by means of polyphosphate, marked technetium 99 Tc ( 99 Tc of 1-hydroxy-etili-den-1,1 - dinatrium phosphonate), allows to find more intensive accumulation of drug in places of the increased and pathological exchange in bones and earlier to diagnose O. of N, and also to track efficiency of treatment in dynamics. Calcification of vessels comes to light radiological, they become visible in a survey picture. For the purpose of diagnosis of ectopic calcification at O. in N the biopsy of soft tissues and survey of eyes by means of a slit lamp can be made. Quite often calcification of soft tissues around joints, sinews and in skin comes to light. At uraemia adjournment of salts of calcium and in a mammary gland is possible. Localization of the hypertrophied and adenomatously changed epithelial bodies can be specified with the help scannings (see). The biopsy of a bone tissue at O. of N allows to define the nature of cellular reaction, a condition of bone structures, extent of accumulation of osteoid.

At identification of dystrophic changes in a skeleton the differential diagnosis is carried out first of all between O. by N at a renal failure and tubulopatiya (decrease in clearance of creatinine, existence of an azotemia, lack of laboratory symptoms of the isolated tubular dysfunction), and also with osteodystrophies of an extrarenal origin (see. Osteodystrophy ), endocrinopathies, including. hyperparathyreosis (see), postclimacteric and alimentary osteoporosis (see); imperfect bone formation (see. Bone formation imperfect ), multiple myeloma (see), Pedzhet's disease (see. Pedzheta disease ), poisoning with fluorine, diffusion osteoklastichesky process of the tumoral nature, sarcoidosis (see).


Treatment is begun preventively with the moment of development or detection of a renal failure and continued in combination with methods of extrarenal clarification. The complex to lay down. actions it is directed to elimination of acidosis, a hyperphosphatemia and deficit of vitamin D. Drugs of magnesium are contraindicated, as antiacid means and a sorbent of phosphate appoint aluminum hydroxide. At treatment hemodialysis (see) it is necessary that the dialyzing solution contained enough calcium, excess of phosphate from blood completely was removed and acidosis korrigirovatsya. The diet shall not include the products rich with phosphorus and to-tami (e.g., bean, marinades).

Treatment by vitamin D of patients, at to-rykh symptoms of osteomalacy prevail, begin with rather small doses — 6000 — 10 000 ME a day. Lech. the effect is shown 3 — 4 months later; weakness and pains disappear, datum level of calcium, parathormone and an alkaline phosphatase in blood is recovered, density of bones increases. After normalization a lab. indicators the dose of vitamin D is reduced. In case of the expressed hyperparathyreosis and resistance to vitamin D the last is appointed in high doses (150 000 — 200 000 ME a day), carefully controlling the level of calcium and phosphate in blood since during treatment sensitivity of an organism to vitamin D can change or progress ectopic calcification. Also Dihydrotachysterolum is effective (0,25 — 0,375 mg a day).

Improvement of results of treatment of O. of N is connected using 1 hydroxycholecalciferol. This drug does not need metabolic activation by kidneys; it normalizes absorption of calcium and secretion of parathormone. The initial dose 1 - hydroxycholecalciferol makes 0,5 — 2,5 mkg a day, in the subsequent it can be increased to 10 mkg a day. On reaching the desirable to lay down. effect the dose of drug is gradually reduced to supporting — 0,25 — 1,0 mkg a day. At insufficient efficiency of conservative treatment and the accruing manifestations of ectopic calcification timely subtotal is shown parathyroidectomy (see).

O.'s treatment N at tubulopatiya at teenagers and adults essentially does not differ from treatment at uraemia and is based on use in high doses of drugs of vitamin D, salts of calcium, phosphorus, correction of acidosis by oral administration of citric acid in a combination with its potassium and sodium salts. At a hyperphosphatemia sorbents of phosphate (aluminum hydroxide, active coal) are shown to patients.

The forecast

Due to the irreversible changes of a skeleton and calcification of soft tissues of O. of N complicates rehabilitation of patients with a renal failure, and in hard cases can be the cause of a lethal outcome.

Nephrogenic an osteopathy at children

N at children represent O. not only O. at hron, a renal failure, but also group of the diseases and syndromes combining under the general name of a tubulopatiya, to-rye the caused or secondary disturbances of canalicular functions of nephron owing to euzymatic defects include hereditarily (see. Enzymopathies ). Distinguish genetic, or primary, defects in fermental systems and secondary, caused by earlier postponed glomerulonephritis, pyelonephritis, toxic damage of kidneys at anomalies of exchange, use of nephrotoxic pharmaceuticals.

The lake of N arises also at disturbance of processes of a hydroxylation of vitamin D and its transformation into hormone (1 alpha, 2,5 dihydroxycholecalciferol). This pathogenetic mechanism is the cornerstone of an osteopathy at hron. renal failure. In this regard the N caused by primary tubulopatiya should carry vitamin to O. - D-resistant rickets (see Phosphate diabetes), de Tony's syndrome — Debra — Fang horses (see De Tony — Debra — Fankoni a syndrome), renal canalicular acidosis (see Laytvud — Albright a syndrome), nefronoftiz Fankoni (see. Fankoni nefronoftiz ), Lowe's syndrome (see. Lowe syndrome ).

Changes of a homeostasis and damage of kidneys at such diseases as vitamin are the cornerstone of secondary disturbances of renal regulation of phosphorus-calcium exchange - D-scarce rickets (see), malabsorption syndrome (see), Gee's disease (see), hypophosphatasia (see), and pseudohypoparathyroidism (see), primary hyperparathyreosis (see), cystinosis (see), hron, tyrosinosis (see), glycogenosis (see), poisoning with salts of heavy metals and other nephrotoxic substances, and also hron. renal failure (see). All these diseases which are characterized by changes from bone system at children before establishment of the exact diagnosis carry to so-called rakhitopodobny diseases.

Early manifestations of disturbance of phosphorus-calcium exchange are observed at rickets, a hypophosphatasia, Lowe's syndrome, a cystinosis, a tyrosinosis. An osteopathy at children with vitaminodefitsitny rickets come to light during rapid growth, at Laytvud's syndrome at the age of 5 — 6 months, the majority of nephrogenic osteopatiya clinically comes to light after the first year of life when the child starts walking. At Fankoni's nefro-noftiza a wedge, O.'s manifestations N arise usually at teenage age when the chronic renal failure develops.

Pathoanatomical changes of bone system at adults and children differ in nek-ry features. At O. of N the changes which are very reminding rachitic are found in children in bones. Therefore this form of a disease is known under the name «renal rickets». Microscopically in bones of a skeleton at renal rickets unlike usual rickets excess accumulation of cartilaginous masses is not observed, but their rassasyvaniye and replacement can occur as well as at D-avitaminosis. Changes of bones are characterized by their intensive reorganization which is expressed in various degree of a resorption and a new growth of the bone substance which is not exposed to full calcification. Essentially these changes differ from O. in N at adults a little. However owing to disturbances of an osteogenesis of the growing organism such osteopathy leads to a growth inhibition and deformation of bones of a skeleton. Microscopically chaotic heaps of not calciphied ossiform substance are found in those departments of a skeleton, to-rye most strenuously grow and are reconstructed at this age.

Numerous options of damage of bones of a skeleton at O. of N at children speak as character and duration of primary disease of kidneys, and age, in Krom the disease of kidneys for the first time was found.

Early diagnosis of O. of N at children includes researches of a ratio in urine and blood of phosphorus, calcium, amino acids, activities of an alkaline phosphatase, in particular fractions of an isoenzyme of a bone alkaline phosphatase. Assessment funkts, conditions of a liver, kidneys where there is an activation of D3 vitamin, and also thyroid and the epithelial bodies synthesizing thyrocalcitonin (see is of great importance. Kaltsitonin ), iaratireoidny hormone, and other systems regulating phosphorus-calcium exchange. Biochemical, researches in O.'s diagnosis N are dominating since a wedge, manifestations are same. Depending on changes of bone system there are distinctions in a wedge, a current: varus deformation is noted at vitamin - D - pe-zistentnom rickets, valgus — at renal canalicular acidosis, multiple changes — at de Tony's syndrome — Debra — Fankoni, vitamin-]) - the manager and with and mo in m rickets. Content of the general calcium in blood usually within norm or is slightly reduced. Big information is given by researches of the ionized calcium, level to-rogo in blood at renal tubulopatiya is considerably raised. In blood it is possible to determine localization of defeat of nephron by the level of phosphorus. Low level is characteristic of disturbance of a reabsorption of phosphorus in a proximal tubule, high — at disturbance of its secretion in distal department of nephron (psevdogipoparati-reoidizm). The hyperphosphaturia is characteristic for phosphate diabetes, vitamin - D-resistant rickets, de Tony's syndrome — Debra — Fankoni, a hypophosphaturia — of the acquired and inborn defeats of distal department of nephron. De Tony-Debra's syndrome — Fankoni as well as vitamin - D-scarce and vitamin D - dependent rickets, is followed by the increased removal with urine of amino acids. Melituria (see) it is noted at de Tony's syndrome — Debra — Fankoni. At O. of N at children (except phosphate diabetes) metabolic develops acidosis (see). Disturbance of functions of nephron at O. of N concerns resistance of tubules to hormones, in particular to parathyroid that promotes development of a secondary hyper parathyroidism. Researches 1 an alpha, 2, 5-dihydroxy-cholecalciferol belong to thinner methods of differential diagnosis of O. of N. Decrease in level of this hormone is observed at hron. a renal failure, renal canalicular acidosis and vitamin - D-resistant rickets. Definition of glikozaminoglikan, oxyproline in urine at O. the N at children has no certain differential and diagnostic value since their excretion in all cases is lowered. Only at the acquired damages of kidneys the content of these substances in urine can be increased.

Rentgenol, a picture of a skeleton at O. of N at children does not differ from a classical picture of rickets. Zones of preparatorny calcification, especially near knee, radiocarpal, shoulder joints are expanded, in hard cases all bones of a skeleton are surprised. Their sharp osteoporosis develops — the structure becomes shirokopetlisty, the thinned bone beams consisting from, the cortical layer also becomes thinner, loses the compactness and density, takes a friable form. Both bones of shins and forearms become almost equal on thickness. The osteoporosis defined radiological is caused by osteomalacic changes of bones. Similar changes undergo short bones of brushes, feet; formation of an epiphysis, bones of a wrist and a tarsus is late. Growth is sharply slowed down, funkts, possibilities of bones decrease, appear single, and then and multiple zones patol, funkts, reorganizations in the beginning (see. Loozera of a zone ), at the level of which there is a compensatory periosteal osteogenesis. Long tubular bones of the lower extremities are bent, along concave surfaces of a diaphysis longitudinal equal periosteal stratifications are formed. Zones patol, funkts, reorganizations in edges are shown by their chetkoobrazny thickenings.

Fig. 5. Roentgenograms of the left and right forearms of the three-year-old boy with a nephrogenic osteopathy: bones of forearms are equal on thickness, cortical substance is thinned, sharp osteoporosis; shooters specified zones of pathological functional reorganization.

Metaphyses of long tubular bones are thickened, take a bowl-shaped form that is caused by a delay of calcification of the ossiform beams which are formed near the region of growth (fig. 5).

Differential diagnosis of O. of N at children is carried out about vitamin D - scarce rickets (see), hypophosphatasia (see), imperfect bone formation (see. Bone formation imperfect ), a chondrodystrophia (see), malabsorption by a syndrome (see), with an idiopathic hypercalcemia of children's age (see. Hypercalcemia ). At differential diagnosis with rickets time of emergence of changes from bone system of the child matters. A wedge, displays of rickets usually are found early, at the age of 1,5 — 3 months and are followed by a gi-peraminoatsiduriya (see. Aminoatsiduriya ) and metabolic acidosis. The hypophosphatasia is shown also in the first months of life of the child and characterized by the lowered content or lack of an alkaline phosphatase in blood and the raised excretion of phosphoethanolamine with urine. Cystinosis (see) on clinic and biochemical .sdviga it is similar to de Tony's syndrome — Debra — Fankoni; its diagnosis is based on detection of crystals of cystine in a cornea and in leukocytes. For Lowe's syndrome (see. Lowe syndrome ) simultaneous damage of eyes, c is characteristic. N of page and the increased removal with urine of ketonic acids. At hron, tyrosinosis (see) the gepatosplenomegaliya, jaundice and a hemorrhagic syndrome takes place.

Fig. 6. The roentgenogram of shins of the patient with a nephrogenic osteopathy: osteosclerosis and curvature of tubular bones.

The osteosclerosis in many bones of a skeleton, including in pelvic bones on edge of acetabular hollows, in frontal and main bones of a skull, a shovel is characteristic of an idiopathic hypercalcemia. Also bodies of vertebras, short bones of a wrist and a tarsus are condensed. In long tubular bones the osteosclerosis is localized generally in metaphyses, having either a continuous or taenioid appearance. Long tubular bones, especially lower extremities, at the same time are bent (fig. 6).

The general principles of therapy of O. of N include the actions improving absorption of calcium and vitamin D, its activation in a liver and kidneys and turning into hormone (1 alpha, 2, 5-dihydroxycholecalciferol). Activation of the enzymatic systems which are carrying out a gidroksplirovaniye of vitamin D is possible at administration of such drugs as phenobarbital. In the absence of effect high doses of vitamin D are appointed 3 and its hydroxylated forms; high doses of drugs of phosphorus and calcium are applied. Treatment is carried out under control of content of phosphorus to blood, by activities of an alkaline phosphatase and removal of calcium and phosphorus with urine. Operational correction of bone deformations is carried out not earlier, than in 2 years after permanent kliniko-biochemical remission.

O.'s prevention N at children consists in treatment of a basic disease. The earlier treatment is begun, the less often there are indications to operational correction of bone deformations.

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