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Nguyen Ngoc Hung - One of the best experts on this subject based on the ideXlab platform.
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derotational osteotomy of the Proximal Radius and the distal ulna for congenital radioulnar synostosis
Journal of Children's Orthopaedics, 2008Co-Authors: Nguyen Ngoc HungAbstract:Abstract Objective To evaluate the clinical and functional results of a technical procedure in the surgical treatment of congenital radioulnar synostosis in children. Materials and methods A prospective study had been undertaken from January 1992 to December 2004. Thirty-four patients with congenital radioulnar synostosis that are fixed in pronation were recruited. Congenital radioulnar synostosis was classified for two types according to Tachdjian’s criteria. All patients were treated by resection of the Proximal Radius and the distal ulna to remove a segmental bone of both parts of the forearm. After K-wires are inserted intramedullarly into both bones, the forearm is derotated manually, followed by cast immobilization. Results There were 34 patients (52 forearms) with congenital radioulnar synostosis, whom the average age at surgery was 6 years and 3 months. There were two types of congenital radioulnar synostosis: Type 1 in six forearms (11.6%) and Type 2 in 46 forearms (88.4%). The preoperative forea...
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derotational osteotomy of the Proximal Radius and the distal ulna for congenital radioulnar synostosis
Journal of Children's Orthopaedics, 2008Co-Authors: Nguyen Ngoc HungAbstract:Objective To evaluate the clinical and functional results of a technical procedure in the surgical treatment of congenital radioulnar synostosis in children.
Eckhard Schoenau - One of the best experts on this subject based on the ideXlab platform.
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peripheral quantitative computed tomography of the Proximal Radius in young subjects new reference data and interpretation of results
Journal of Musculoskeletal & Neuronal Interactions, 2008Co-Authors: Frank Rauch, Eckhard SchoenauAbstract:The aim of this contribution is to provide reference data for peripheral quantitative computed tomography (Stratec XCT2000 ® ) performed at the Proximal Radius (the so-called ‘65% site’) of young subjects and to discuss the interpretation of such analyses. Data from a previous reference data study on 469 subjects between 6 and 40 years were re-analyzed and smooth curves were fitted. The corresponding equations allow for calculation of age-, height- and sex-specific z-scores of total crosssectional area, cortical cross-sectional area, bone mineral content, cortical bone mineral density, total bone mineral density, Strength-Strain Index, muscle cross-sectional area and the ratio between bone mineral content and muscle cross-sectional area. These data should facilitate the clinical use of peripheral quantitative computed tomography in young subjects.
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adrenarche and bone modeling and remodeling at the Proximal Radius weak androgens make stronger cortical bone in healthy children
Journal of Bone and Mineral Research, 2003Co-Authors: Thomas Remer, Eckhard Schoenau, C M Neu, Friedrich Manz, Kai R Boye, Michaela F Hartmann, Stefan A WudyAbstract:Adrenarche, the physiological increase in adrenal androgen secretion, may contribute to better bone status. Proximal radial bone and 24-h urinary steroid hormones were analyzed cross-sectionally in 205 healthy children and adolescents. Positive adrenarchal effects on radial diaphyseal bone were observed. Obviously, adrenarche is one determinant of bone mineral status in children. Introduction: Increased bone mass has been reported in several conditions with supraphysiological adrenal androgen secretion during growth. However, no data are available for normal children. Therefore, our aim was to examine whether adrenal androgens within their physiological ranges may be involved in the strengthening of diaphyseal bone during growth. Methods: Periosteal circumference (PC), cortical density, cortical area, bone mineral content, bone strength strain index (SSI), and forearm cross-sectional muscle area were determined with peripheral quantitative computed tomography (pQCT) at the Proximal radial diaphysis in healthy children and adolescents. All subjects, aged 6–18 years, who collected a 24-h urine sample around the time of their pQCT analysis (100 boys, 105 girls), were included in the present study, and major urinary glucocorticoid (C21) and androgen (C19) metabolites were quantified using gas chromatography-mass spectrometry. Results and Conclusions: We found a significant influence of muscularity, but not of hormones, on periosteal modeling (PC) before the appearance of pubic hair (prepubarche). Similarly, no influence of total cortisol secretion (C21) was seen on the other bone variables. However, positive effects of C19 on cortical density (p < 0.01), cortical area (p < 0.001), bone mineral content (p < 0.001), and SSI (p < 0.001)—reflecting, at least in part, reduction in intracortical remodeling—were observed in prepubarchal children after muscularity or age had been adjusted for. This early adrenarchal contribution to Proximal radial diaphyseal bone strength was further confirmed for all cortical variables (except PC) when, instead of C19 and C21, specific dehydroepiandrosterone metabolites were included as independent variables in the multiple regression model. During development of pubic hair (pubarche), muscularity and pubertal stage rather than adrenarchal hormones seemed to influence bone variables. Our study shows that especially the prepubarchal increase in adrenal androgen secretion plays an independent role in the accretion of Proximal radial diaphyseal bone strength in healthy children.
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gender specific pubertal changes in volumetric cortical bone mineral density at the Proximal Radius
Bone, 2002Co-Authors: Eckhard Schoenau, C M Neu, Frank Rauch, Friedrich ManzAbstract:It is well established that puberty affects the geometry of cortical bone differently in females and males. In the present study we investigated whether there are also gender differences in the volumetric bone mineral density of the cortical compartment (BMDcort). BMDcort was determined at the Proximal radial diaphysis in 362 healthy children and adolescents (age 6-23 years; 185 females, 177 males) and in 107 adults (age 29-40 years; 88 women, 19 men) using peripheral quantitative computed tomography (pQCT). The densitometric result for BMDcort was similar in prepubertal girls and boys, but was significantly higher in females after pubertal stage 3. pQCT results for BMDcort are influenced by cortical thickness due to the partial volume effect. Therefore, these gender differences were reanalyzed in groups of subjects of the same developmental stage who were matched for cortical thickness. Thus calculated, no gender difference in BMDcort was detected in prepubertal children. However, adolescent females after pubertal stage 3 and adult women had a 3%-4% higher BMDcort than males at the same developmental stage. BMDcort is an integrated measure of both cortical porosity and mean material density of cortical bone. The metabolic activity of cortical bone (intracortical remodeling) increases cortical porosity and decreases the mean material density of cortical bone. Our results therefore suggest that intracortical remodeling is lower in postpubertal females than in males.
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the development of bone strength at the Proximal Radius during childhood and adolescence
The Journal of Clinical Endocrinology and Metabolism, 2001Co-Authors: Eckhard Schoenau, C M Neu, Frank Rauch, Friedrich ManzAbstract:Current investigations of bone development mostly focus on bone mass, but bone strength may be functionally more important than mass. Therefore, we compared the developmental changes in cortical bone mass (BMCcort) and parameters of cortical bone strength [polar moment of inertia, section modulus, and strength strain index (SSI)]. Analyses were performed at the 65% site of the Proximal Radius using peripheral quantitative computed tomography. The study population comprised 469 healthy subjects, 6-40 yr of age (273 females). Both in prepubertal children (pubertal stage 1) and after puberty (pubertal stage 5 and adults) all studied parameters were significantly higher in males. During puberty (pubertal stages 2-4) the gender-specific differences were generally somewhat smaller. All of the measured parameters increased significantly with age and pubertal stage. However, although the percent increase in BMCcort between the youngest children and adults was similar between the genders, the increases in polar moment of inertia, section modulus, and SSI were higher in males. The ratio between section modulus and BMCcort was consistently higher in males after the age of 11 yr and after pubertal stage 2. Similar results were found for ratios between polar moment of inertia or SSI and BMCcort. These results show that for a given bone mass, males have stronger bones than females after pubertal stage 2. This reflects the fact that in puberty males add bone mostly on the periosteal surface, where the effect on bone strength is highest, whereas females add bone on the endocortical surface, which has a small effect on bone stability. The purpose of the mechanically inefficient endocortical apposition in female puberty might be to create a reservoir of calcium for future pregnancy and lactation.
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the development of bone strength at the Proximal Radius during childhood and adolescence
The Journal of Clinical Endocrinology and Metabolism, 2001Co-Authors: Eckhard Schoenau, Frank Rauch, Friedrich ManzAbstract:Current investigations of bone development mostly focus on bone mass, but bone strength may be functionally more important than mass. Therefore, we compared the developmental changes in cortical bone mass (BMCcort) and parameters of cortical bone strength [polar moment of inertia, section modulus, and strength strain index (SSI)]. Analyses were performed at the 65% site of the Proximal Radius using peripheral quantitative computed tomography. The study population comprised 469 healthy subjects, 6–40 yr of age (273 females). Both in prepubertal children (pubertal stage 1) and after puberty (pubertal stage 5 and adults) all studied parameters were significantly higher in males. During puberty (pubertal stages 2–4) the gender-specific differences were generally somewhat smaller. All of the measured parameters increased significantly with age and pubertal stage. However, although the percent increase in BMCcort between the youngest children and adults was similar between the genders, the increases in polar mo...
Friedrich Manz - One of the best experts on this subject based on the ideXlab platform.
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adrenarche and bone modeling and remodeling at the Proximal Radius weak androgens make stronger cortical bone in healthy children
Journal of Bone and Mineral Research, 2003Co-Authors: Thomas Remer, Eckhard Schoenau, C M Neu, Friedrich Manz, Kai R Boye, Michaela F Hartmann, Stefan A WudyAbstract:Adrenarche, the physiological increase in adrenal androgen secretion, may contribute to better bone status. Proximal radial bone and 24-h urinary steroid hormones were analyzed cross-sectionally in 205 healthy children and adolescents. Positive adrenarchal effects on radial diaphyseal bone were observed. Obviously, adrenarche is one determinant of bone mineral status in children. Introduction: Increased bone mass has been reported in several conditions with supraphysiological adrenal androgen secretion during growth. However, no data are available for normal children. Therefore, our aim was to examine whether adrenal androgens within their physiological ranges may be involved in the strengthening of diaphyseal bone during growth. Methods: Periosteal circumference (PC), cortical density, cortical area, bone mineral content, bone strength strain index (SSI), and forearm cross-sectional muscle area were determined with peripheral quantitative computed tomography (pQCT) at the Proximal radial diaphysis in healthy children and adolescents. All subjects, aged 6–18 years, who collected a 24-h urine sample around the time of their pQCT analysis (100 boys, 105 girls), were included in the present study, and major urinary glucocorticoid (C21) and androgen (C19) metabolites were quantified using gas chromatography-mass spectrometry. Results and Conclusions: We found a significant influence of muscularity, but not of hormones, on periosteal modeling (PC) before the appearance of pubic hair (prepubarche). Similarly, no influence of total cortisol secretion (C21) was seen on the other bone variables. However, positive effects of C19 on cortical density (p < 0.01), cortical area (p < 0.001), bone mineral content (p < 0.001), and SSI (p < 0.001)—reflecting, at least in part, reduction in intracortical remodeling—were observed in prepubarchal children after muscularity or age had been adjusted for. This early adrenarchal contribution to Proximal radial diaphyseal bone strength was further confirmed for all cortical variables (except PC) when, instead of C19 and C21, specific dehydroepiandrosterone metabolites were included as independent variables in the multiple regression model. During development of pubic hair (pubarche), muscularity and pubertal stage rather than adrenarchal hormones seemed to influence bone variables. Our study shows that especially the prepubarchal increase in adrenal androgen secretion plays an independent role in the accretion of Proximal radial diaphyseal bone strength in healthy children.
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gender specific pubertal changes in volumetric cortical bone mineral density at the Proximal Radius
Bone, 2002Co-Authors: Eckhard Schoenau, C M Neu, Frank Rauch, Friedrich ManzAbstract:It is well established that puberty affects the geometry of cortical bone differently in females and males. In the present study we investigated whether there are also gender differences in the volumetric bone mineral density of the cortical compartment (BMDcort). BMDcort was determined at the Proximal radial diaphysis in 362 healthy children and adolescents (age 6-23 years; 185 females, 177 males) and in 107 adults (age 29-40 years; 88 women, 19 men) using peripheral quantitative computed tomography (pQCT). The densitometric result for BMDcort was similar in prepubertal girls and boys, but was significantly higher in females after pubertal stage 3. pQCT results for BMDcort are influenced by cortical thickness due to the partial volume effect. Therefore, these gender differences were reanalyzed in groups of subjects of the same developmental stage who were matched for cortical thickness. Thus calculated, no gender difference in BMDcort was detected in prepubertal children. However, adolescent females after pubertal stage 3 and adult women had a 3%-4% higher BMDcort than males at the same developmental stage. BMDcort is an integrated measure of both cortical porosity and mean material density of cortical bone. The metabolic activity of cortical bone (intracortical remodeling) increases cortical porosity and decreases the mean material density of cortical bone. Our results therefore suggest that intracortical remodeling is lower in postpubertal females than in males.
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the development of bone strength at the Proximal Radius during childhood and adolescence
The Journal of Clinical Endocrinology and Metabolism, 2001Co-Authors: Eckhard Schoenau, C M Neu, Frank Rauch, Friedrich ManzAbstract:Current investigations of bone development mostly focus on bone mass, but bone strength may be functionally more important than mass. Therefore, we compared the developmental changes in cortical bone mass (BMCcort) and parameters of cortical bone strength [polar moment of inertia, section modulus, and strength strain index (SSI)]. Analyses were performed at the 65% site of the Proximal Radius using peripheral quantitative computed tomography. The study population comprised 469 healthy subjects, 6-40 yr of age (273 females). Both in prepubertal children (pubertal stage 1) and after puberty (pubertal stage 5 and adults) all studied parameters were significantly higher in males. During puberty (pubertal stages 2-4) the gender-specific differences were generally somewhat smaller. All of the measured parameters increased significantly with age and pubertal stage. However, although the percent increase in BMCcort between the youngest children and adults was similar between the genders, the increases in polar moment of inertia, section modulus, and SSI were higher in males. The ratio between section modulus and BMCcort was consistently higher in males after the age of 11 yr and after pubertal stage 2. Similar results were found for ratios between polar moment of inertia or SSI and BMCcort. These results show that for a given bone mass, males have stronger bones than females after pubertal stage 2. This reflects the fact that in puberty males add bone mostly on the periosteal surface, where the effect on bone strength is highest, whereas females add bone on the endocortical surface, which has a small effect on bone stability. The purpose of the mechanically inefficient endocortical apposition in female puberty might be to create a reservoir of calcium for future pregnancy and lactation.
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the development of bone strength at the Proximal Radius during childhood and adolescence
The Journal of Clinical Endocrinology and Metabolism, 2001Co-Authors: Eckhard Schoenau, Frank Rauch, Friedrich ManzAbstract:Current investigations of bone development mostly focus on bone mass, but bone strength may be functionally more important than mass. Therefore, we compared the developmental changes in cortical bone mass (BMCcort) and parameters of cortical bone strength [polar moment of inertia, section modulus, and strength strain index (SSI)]. Analyses were performed at the 65% site of the Proximal Radius using peripheral quantitative computed tomography. The study population comprised 469 healthy subjects, 6–40 yr of age (273 females). Both in prepubertal children (pubertal stage 1) and after puberty (pubertal stage 5 and adults) all studied parameters were significantly higher in males. During puberty (pubertal stages 2–4) the gender-specific differences were generally somewhat smaller. All of the measured parameters increased significantly with age and pubertal stage. However, although the percent increase in BMCcort between the youngest children and adults was similar between the genders, the increases in polar mo...
V Braga - One of the best experts on this subject based on the ideXlab platform.
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the volumetric bone density and cortical thickness in adult patients affected by osteogenesis imperfecta
Journal of Clinical Densitometry, 2003Co-Authors: Davide Gatti, V Braga, Maurizio Rossini, F Colapietro, Elena Fracassi, Elisabetta Sartori, Franco Antoniazzi, Silvano AdamiAbstract:Abstract In patients with osteogenesis imperfecta (OI), a disease characterized by abnormal bone fragility, bone mineral density (BMD) was found to be relatively preserved. Quantitative computed tomography (QCT) is the only available method for directly measuring in vivo both volumetric density and the cross-sectional area. Here we report the data from dual-energy X-ray absorptiometry DXA (spine and hip) and peripheral (pQCT) (ultradistal and Proximal Radius) measurement of 27 adult patients affected by OI, mostly of type I, compared with a group of healthy persons. In the patients with OI, areal BMD values at both femoral neck and lumbar spine were considerably lower than in control subjects (–32 and –36%, respectively; p p
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site specific effects of strength training on bone structure and geometry of ultradistal Radius in postmenopausal women
Journal of Bone and Mineral Research, 1999Co-Authors: M Silvano D Adami, Davide Gatti, V Braga, Donatella Bianchini, Maurizio RossiniAbstract:Knowledge of the effects of exercise on bone mass in postmenopausal women is limited and controversial. Animal studies have shown that the response of bone to bending strain is an alteration of bone geometry. We studied 250 postmenopausal women, aged 52-72 years, willing to participate in a 6-month exercise program. The first 125 started the program immediately and the remaining 125 served as controls. The training program included exercises designed to maximize the stress on the wrist. One hundred and eighteen of the active group and 116 of the control group completed the study and were reassessed 6 months later. Bone mineral density (BMD) of the femoral neck, lumbar spine, ultradistal and Proximal Radius was measured by dual-energy X-ray absorptiometry (DXA) both before and at the end of the exercise program. The forearm was also evaluated by peripheral quantitative computed tomography, which measures the area, bone mineral content (BMC), and volumetric density for both the cortical and the trabecular component. The results showed that the DXA measurements at the femoral neck, lumbar spine, ultradistal and Proximal Radius were similar between the two groups. No significant difference was detected after the exercise program at the Proximal Radius. At the ultradistal Radius, the cross-sectional area of cortical bone rose by 2.8 +/- 15.0% (SD, p < 0.05), apparently for both periosteal apposition and corticalization of the trabecular tissue. The volumetric density of cortical bone rose by 2. 2 +/- 15.8% (p < 0.1), and that of trabecular bone decreased by 2.6 +/- 10.7% (p < 0.01). The combined changes in both bone volume and density in the exercise group were associated with marked increase in cortical BMC (3.1 +/- 10.7%, p < 0.01) and decrease in trabecular BMC (-3.4 +/- 14.2%, p < 0.05), which were statistically different from those observed in the control group (p < 0.05). In conclusion, these results confirm that site-specific moderate physical exercises have very little effect on bone mass. However, it appears that some exercises may reshape the bone segment under stress by increasing both the cross-sectional area and the density of the cortical component. These structural changes are theoretically associated with increases in the bending strength.
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Effect of aging on trabecular and compact bone components of Proximal and ultradistal Radius
Osteoporosis International, 1996Co-Authors: D. Gatti, V Braga, M. Rossini, N. Zamberlan, E. Fracassi, S. AdamiAbstract:Bone densitometry has become a major tool for osteoporosis risk assessment. The traditional dual-energy X-ray absorptiometry (DXA) methods are able to evaluate the bone mineral content (BMC; mg/cm) and the areal density (BMD; mg/cm^2), but only quantitative computed tomography (QCT) has the potential to measure the true volumetric bone density in the sense of mass per unit volume (mg/cm^3). Peripheral QCT (pQCT) measurements were carried out at the non-dominant Radius using a Stratec XCT 960 (Unitrem, Roma) in 241 postmenopausal and 29 premenopausal women. The sites of evaluation were both the ultradistal and the Proximal Radius. The technique used has a coefficient of variation of 2% and it allows separation of the bone section into trabecular and cortical bone on the basis of density threshold. Bone mass of Radius, hip and spine was also evaluated by DXA procedures. The bone density data obtained by pQCT were significantly correlated with all DXA measurements. The correlation coefficients between their respective BMD values ranged from 0.48 to 0.75, but for the BMC values of the Radius the correlation coefficients ranged from 0.82 to 0.93. The BMD values measured by DXA, but not by pQCT, were positively related with patient heights. All pQCT density measurements, including those obtained at the Proximal Radius and containing exclusively cortical bone, where negatively related with age and years since menopause. A partial volume effect, which is increasingly relevant the thinner are the bone cortices, might explain that. However, by applying increasing density thresholds, cortical bone density seems to decrease with age as a consequence of a gradual density diminution from the inner part of the bone cortex outwards. Trabecular bone density decreases with aging, but its overall mass does not change as a consequence of an age-related enlargement of trabecular area. Thus, the proportion of trabecular bone over total bone rises, and this might be relevant for our understanding of the age-related changes in bone turnover and rate of bone loss.
L Steven M D Moran - One of the best experts on this subject based on the ideXlab platform.
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combined composite osteofasciocutaneous fibular free flap and radial head arthroplasty for reconstruction of the elbow joint
Microsurgery, 2014Co-Authors: Nick A Van Alphen, T Matthew M D Houdek, S Scott M D Steinmann, L Steven M D MoranAbstract:Reconstruction of the radial head can be complicated in cases of wide resection, particularly in those cases including the Proximal radial shaft. In such cases, radial head replacement may not be possible because of lack of adequate bone stock. Here, we report the use of a radial head prosthesis incorporated with a vascularized fibula for immediate anatomic restoration of the forearm and elbow. We present a case of a pathologic fracture non-union in the Proximal Radius in a 57-year-old female with a history of multiple myeloma. Non-operative management of the fracture was unsuccessful after chemotherapy and radiation. The Proximal Radius and radial head were resected and reconstructed with vascularized fibula graft in conjunction with immediate radial head prosthesis. The osteotomy site healed at 6-weeks and follow-up at 1 year showed good functional outcome. We feel that the use of this construct has definite promise and may be considered for reconstruction following resection of the Proximal Radius. © 2014 Wiley Periodicals, Inc. Microsurgery 34:475–480, 2014.
