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Vitamin D insufficiency and bone mineral density in African American children with forearm fractures
S98
Abstracts / Bone 45 (2009) S59–S111
Results: 59 subjects (32% of survivors) were studied. Those randomised to standard PN solution had lower lumbar spine BMC; apparently explained by a concomitant decrease in bone size. In nonrandomised analyses, subjects exposed to neonatal aluminium intakes above the median (55 mcg/kg) had lower hip BMC (by 7.6% (95% CI 0.21 to 2.38; p = 0.02)), independent of bone (or body) size. Conclusion: Neonates exposed to parenteral aluminium may have reduced lumbar spine and hip bone mass during adolescence, potential risk factors for later osteoporosis and hip fracture. These findings ideally need confirmation in larger, more detailed studies. Nevertheless, given our previous finding of adverse developmental outcome in these subjects, and the sizeable number of contemporary infants undergoing intensive neonatal care who are still exposed to aluminium via parenteral feeding solutions, the potential adverse long term consequences of early aluminium exposure deserve renewed attention. doi:10.1016/j.bone.2009.04.153
PF-08 Inter-individual variation in skeletal growth patterns is predictable based on bone robusticity S. Bholaa, N. Pandeya, R. Ghillanib, K.J. Jepsena a Leni and Peter W. May Department of Orthopaedics, Mount Sinai School of Medicine, New York, NY, USA b Department of Orthopaedic Surgery, Elmhurst Hospital, Elmhurst, NY, USA Adults acquire unique sets of morphologic and tissue-quality bone traits that are predictable based on robusticity, and are deterministic of strength and fragility. However, how and when individual trait sets arise during growth has not been established. Classical studies reported typical growth patterns but did not address variation in robusticity among individuals. Robusticity, which defines the relationship between growth in width and growth in length of long bones, is a heritable trait that varies widely among individuals. Longitudinal structural changes of the metacarpal diaphysis were measured in children from 3 months to 18 years of age using hand radiographs from the Bolton–Brush collection. Within each gender, robusticity varied ∼2-fold among children, and individual values were established by 2 years of age, indicating that genetic and environmental factors controlling the relationship between growth in width and length were established early during post-natal growth. Significant negative correlations between robusticity and relative cortical area, and significant positive correlations between robusticity and a novel measure capturing growth efficiency indicated that coordination between sub-periosteal and endosteal surfaces was responsible for the narrow range of trait sets and was predictable based on robusticity. Children with robust diaphyses had proportionally thinner cortices to minimize mass, whereas individuals with slender diaphyses had proportionally thicker cortices to maximize stiffness. Females developed more slender metacarpals with proportionally thicker cortices compared to males. Through puberty, increased sexual dimorphism strengthened these relationships. Finding that growth patterns were consistent across a genetically heterogeneous population suggests that individuals share a common biologic control that buffers variants affecting robusticity, allowing for a range of functional growth patterns. Bone health assessment can be improved by considering the dependence of skeletal growth patterns on robusticity. Application of our findings to novel clinical measures will better quantify genetic and environmental impacts on bone strength and fracture risk. doi:10.1016/j.bone.2009.04.154
Pathogenesis of Fractures PF-09 Non-traumatic avulsion of the greater trochanter: A case report and review of the literature M. El Hachmi, D. Desmette, J.-P. Forthomme Saint Joseph, Mons, Belgium Avulsion fracture of the greater trochanter is a rarity in children. When described in the literature, they are often caused by a traumatic event. We present a case of non traumatic origin which was treated surgically. The aetiology are discussed and the prognosis as well. A 13-year-old boy presented with a progressive right hip pain without any traumatic event. Plain radiograph showed a complete separation of the greater trochanter from the femur. At surgery, no manipulation for reduction was needed. This enabled a percutaneous technique to be performed (in situ). In the pelvis, the most common site of avulsion injuries is the ischial tuberosity. In children, avulsion fractures of the greater trochanter are very rare and they have been classified according to the mechanism causing fracture. So as we know, there is only one case reported in the literature of a greater trochanter avulsion fracture of non-traumatic origin. There is no specific aetiology identified causing this injury. Three papers published recently raised the possible link between the fracture avulsion of the greater trochanter and the slipped capital femoral epiphysis. These authors reported cases with obese male teenagers. So we cannot exclude an inherent weakness in the growth plate. It is important to differentiate a real avulsion fracture which is very rare from a widening of the greater trochanter physis which is a radiologic sign of osteomyelitis in children. The prognosis is reserved because of the great risk of developing avascular necrosis of the femoral head due to the very close blood supply for both anatomic sites (femoral head and greater trochanter). For that reason, we prefer to treat such lesions with careful minimal open reduction to avoid further devascularisation of the immature proximal femur. doi:10.1016/j.bone.2009.04.155
PF-10 Vitamin D insufficiency and bone mineral density in African American children with forearm fractures L.M. Ryan, C. Brandoli, S. Singer, R.J. Freishtat, J.L. Wright, L.L. Tosi, J.M. Chamberlain Children's National Medical Center, Washington, DC, USA Background: Fracture rates in children are increasing. Vitamin D insufficiency (serum 25-hydroxy vitamin D level < 20 ng/mL) is associated with decreased bone mineral density (BMD). The relationship between vitamin D status and childhood fractures has not been investigated. We hypothesize that children with forearm fractures have an increased prevalence of vitamin D insufficiency and decreased BMD compared to fracture-free controls. Design/Methods: This case-control study is enrolling cases (African American children, ages 5–9 years, with forearm fracture) and fracture-free controls. Bone health evaluation includes measurement of serum 25-hydroxy vitamin D level and BMD by dual energy x-ray absorptiometry (DXA) scan. Univariable and multivariable analyses are used to test associations between fracture status and independent variables (serum vitamin D level, BMD) with control for confounding variables.
Abstracts / Bone 45 (2009) S59–S111
Results: To date, 28 cases and 17 controls are enrolled. The mean (±SD) age of cases [7.1 (±1.4) years] and the proportion who were male (61%) did not differ from the controls [7.0 (±1.5) years] and 64% respectively. The mean 25-hydroxy vitamin D level for cases [22.6 (±7.9) ng/mL, (range 10–38 ng/mL)] was significantly lower than that of controls [29.1 (± 7.5) ng/mL, (range 15–46 ng/mL)] (p = 0.009). More cases (11/28, 39%) were vitamin D insufficient compared to controls (2/17, 11.8%, OR = 4.85, 95% CI = 0.92–25.5). All DXA scan results were consistent with normal bony mineralization for age (z-score > −2). The mean total body z-score for cases [0.6 (±0.9)] did not differ significantly from controls [0.9 (±0.9)] (p = 0.25). Conclusions: Mean serum vitamin D levels are significantly lower in African American children with fractures than matched controls. Future analyses will incorporate measurements of calcium and vitamin D intake, physical activity, sun exposure, body mass index and genetic analysis. Vitamin D insufficiency may play a previously unrecognized role in childhood fractures. doi:10.1016/j.bone.2009.04.156
PF-11 Malignant infantile osteopetro-rickets: The paradox of plenty A. Shalash, J. Rajah Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates Objective: The aim of this case report is to highlight: 1) the rare paradoxical presence of rickets in children with osteopetrosis, with its attendant complications. 2) that MIOPR is a medical emergency. Methods: A 3 month infant presented to the orthopedic department with a fracture of the upper third of the R femur. The child was in a cast and in traction. Parents were consanguineous (1st cousins) from Pakistan. Neonatal records revealed that he was investigated for thrombocytopenia. Weight and height measurements were on the 3rd centile. Clinical exam revealed, frontal bossing, widened wrists, roving nystagmus with pale optic disks and 4–5 cm hepatosplenomegaly. Results: Skeletal survey revealed osteopetrosis and rickets as well as the fracture femur. CT scan and MRI showed narrowing at the optic foramina. ALP was 1450 IU/L. Calcium was 2 mmol/L and phosphorus 0.69 mmol/L. Intact PTH was 29.1 pmol/L and 25 hydroxy vit D 14 nmol/L. Treatment consisted of calcium, calcitriol, ergocalciferol and interferon gamma. Conclusions: Unless early diagnosis is made and therapy started, these children die of infection or bleeding (encroachment of marrow space) or get permanent disability (blindness and deafness from compression of the optic and auditory foraminae and nasal obstruction from thickening of nasal bones). Rickets develops paradoxically when the Ca × PO4 product is decreased. Even though total body Ca is increased, it remains “trapped” in bone because of osteoclast dysfunction. Rickets further complicates the picture by promoting fractures, causing further irritability and poor feeding. Osteopetro-rickets may also attenuate the effectiveness of bone marrow transplantation as the new osteoclasts are unable to resorb bone in osteoid. doi:10.1016/j.bone.2009.04.157
PF-12 Multiple bone fractures in children — Environmental determinations A. Rusinska, D. Chlebna-Sokol, I. Michalus, A.M. Prochowska Department of Paediatric Propedeutics and Bone Metabolic Diseases, Medical University of Lodz, Lodz, Poland
S99
Aim: The aim of the study was the analysis of the relationships between selected environmental factors and bone fractures in children. Patients and methods: The study comprised 112 children aged 5–17 years, 81 patients with history multiple bone fractures and 31 healthy patients in control group. In all children densitometric examination of the skeleton with DXA method at total body and spine was taken. Moreover questionnaire examination taking into consideration the environmental factors which are probably connected with bone fractures was carried out. Results: In examined group more children than in controls were inhabitants (90 v. 78%, p < 0.05). The mean fracture number was higher in patients subjected to tobacco smoking (5.3 v. 3.3, p < 0.05). There was no observed relationship between mean time of sunlight exposure or number of children in family and fractures. Fathers of children with fractures predominantly have a vocational education (47%), in control group the most often was mean technical education (35%); there was negative correlation between the father's education and the number of fracture (R = − 0.29, p < 0.05). There was an observed significant relationship between the time of children school physical education and bone mineral density (R = 0.27 i 0.22, p < 0.05). Moreover, there was a negative correlation between the time of physical home activity and fracture number (R = − 0.26, p < 0.05). Conclusions: Multiple bone fractures in children may be also determined by environmental factors. Exposure to tobacco smoking, decreased physical activity and father's education seem to be connected with consecutive fractures in the developmental period. Acknowledgements: The study was partly financed by grant no. N407 063 32/2713. doi:10.1016/j.bone.2009.04.158
PF-13 Bone fractures in children — Evaluation of bone mineral density by dual energy X-ray absorptiometry and quantitative ultrasound D. Chlebna-Sokol, A. Rusinska, J. Golec, I. Michalus Department of Paediatric Propedeutics and Bone Metabolic Diseases, Medical University of Lodz, Lodz, Poland Aim: To evaluate the relationship between densitometry and quantitative ultrasound parameters of bone mineral density and fractures in children. Material and methods: The study involved 380 children aged 5–18 years, including 157 girls and 223 boys. In 10 children vertebral fractures were reported and 177 of them suffered from present or past long bones fractures. Dual energy X-ray absorptiometry and ultrasound examination of calcaneus was performed to assess bone mineral density. Results: The study revealed a statistically significant positive correlation between the results of bone mineralization obtained by densitometry and ultrasounds. The highest correlation coefficients were observed for Stiffness and BUA (broadband ultrasound attenuation) parameters and bone mineral density measured in total body. The analysis of the relationship between bone mineralization measurements and fractures revealed significantly lower mean Zscore parameters both in total body and spine in children with vertebral fractures. The values of ultrasound parameters in this group of patients were also lower, but the differences were not statistically significant. There were no significant differences observed between the patients with and without fractures of long bones for all bone mineralization results, even after detailed analysis in each age group was performed.
Abstracts / Bone 45 (2009) S59–S111
Results: 59 subjects (32% of survivors) were studied. Those randomised to standard PN solution had lower lumbar spine BMC; apparently explained by a concomitant decrease in bone size. In nonrandomised analyses, subjects exposed to neonatal aluminium intakes above the median (55 mcg/kg) had lower hip BMC (by 7.6% (95% CI 0.21 to 2.38; p = 0.02)), independent of bone (or body) size. Conclusion: Neonates exposed to parenteral aluminium may have reduced lumbar spine and hip bone mass during adolescence, potential risk factors for later osteoporosis and hip fracture. These findings ideally need confirmation in larger, more detailed studies. Nevertheless, given our previous finding of adverse developmental outcome in these subjects, and the sizeable number of contemporary infants undergoing intensive neonatal care who are still exposed to aluminium via parenteral feeding solutions, the potential adverse long term consequences of early aluminium exposure deserve renewed attention. doi:10.1016/j.bone.2009.04.153
PF-08 Inter-individual variation in skeletal growth patterns is predictable based on bone robusticity S. Bholaa, N. Pandeya, R. Ghillanib, K.J. Jepsena a Leni and Peter W. May Department of Orthopaedics, Mount Sinai School of Medicine, New York, NY, USA b Department of Orthopaedic Surgery, Elmhurst Hospital, Elmhurst, NY, USA Adults acquire unique sets of morphologic and tissue-quality bone traits that are predictable based on robusticity, and are deterministic of strength and fragility. However, how and when individual trait sets arise during growth has not been established. Classical studies reported typical growth patterns but did not address variation in robusticity among individuals. Robusticity, which defines the relationship between growth in width and growth in length of long bones, is a heritable trait that varies widely among individuals. Longitudinal structural changes of the metacarpal diaphysis were measured in children from 3 months to 18 years of age using hand radiographs from the Bolton–Brush collection. Within each gender, robusticity varied ∼2-fold among children, and individual values were established by 2 years of age, indicating that genetic and environmental factors controlling the relationship between growth in width and length were established early during post-natal growth. Significant negative correlations between robusticity and relative cortical area, and significant positive correlations between robusticity and a novel measure capturing growth efficiency indicated that coordination between sub-periosteal and endosteal surfaces was responsible for the narrow range of trait sets and was predictable based on robusticity. Children with robust diaphyses had proportionally thinner cortices to minimize mass, whereas individuals with slender diaphyses had proportionally thicker cortices to maximize stiffness. Females developed more slender metacarpals with proportionally thicker cortices compared to males. Through puberty, increased sexual dimorphism strengthened these relationships. Finding that growth patterns were consistent across a genetically heterogeneous population suggests that individuals share a common biologic control that buffers variants affecting robusticity, allowing for a range of functional growth patterns. Bone health assessment can be improved by considering the dependence of skeletal growth patterns on robusticity. Application of our findings to novel clinical measures will better quantify genetic and environmental impacts on bone strength and fracture risk. doi:10.1016/j.bone.2009.04.154
Pathogenesis of Fractures PF-09 Non-traumatic avulsion of the greater trochanter: A case report and review of the literature M. El Hachmi, D. Desmette, J.-P. Forthomme Saint Joseph, Mons, Belgium Avulsion fracture of the greater trochanter is a rarity in children. When described in the literature, they are often caused by a traumatic event. We present a case of non traumatic origin which was treated surgically. The aetiology are discussed and the prognosis as well. A 13-year-old boy presented with a progressive right hip pain without any traumatic event. Plain radiograph showed a complete separation of the greater trochanter from the femur. At surgery, no manipulation for reduction was needed. This enabled a percutaneous technique to be performed (in situ). In the pelvis, the most common site of avulsion injuries is the ischial tuberosity. In children, avulsion fractures of the greater trochanter are very rare and they have been classified according to the mechanism causing fracture. So as we know, there is only one case reported in the literature of a greater trochanter avulsion fracture of non-traumatic origin. There is no specific aetiology identified causing this injury. Three papers published recently raised the possible link between the fracture avulsion of the greater trochanter and the slipped capital femoral epiphysis. These authors reported cases with obese male teenagers. So we cannot exclude an inherent weakness in the growth plate. It is important to differentiate a real avulsion fracture which is very rare from a widening of the greater trochanter physis which is a radiologic sign of osteomyelitis in children. The prognosis is reserved because of the great risk of developing avascular necrosis of the femoral head due to the very close blood supply for both anatomic sites (femoral head and greater trochanter). For that reason, we prefer to treat such lesions with careful minimal open reduction to avoid further devascularisation of the immature proximal femur. doi:10.1016/j.bone.2009.04.155
PF-10 Vitamin D insufficiency and bone mineral density in African American children with forearm fractures L.M. Ryan, C. Brandoli, S. Singer, R.J. Freishtat, J.L. Wright, L.L. Tosi, J.M. Chamberlain Children's National Medical Center, Washington, DC, USA Background: Fracture rates in children are increasing. Vitamin D insufficiency (serum 25-hydroxy vitamin D level < 20 ng/mL) is associated with decreased bone mineral density (BMD). The relationship between vitamin D status and childhood fractures has not been investigated. We hypothesize that children with forearm fractures have an increased prevalence of vitamin D insufficiency and decreased BMD compared to fracture-free controls. Design/Methods: This case-control study is enrolling cases (African American children, ages 5–9 years, with forearm fracture) and fracture-free controls. Bone health evaluation includes measurement of serum 25-hydroxy vitamin D level and BMD by dual energy x-ray absorptiometry (DXA) scan. Univariable and multivariable analyses are used to test associations between fracture status and independent variables (serum vitamin D level, BMD) with control for confounding variables.
Abstracts / Bone 45 (2009) S59–S111
Results: To date, 28 cases and 17 controls are enrolled. The mean (±SD) age of cases [7.1 (±1.4) years] and the proportion who were male (61%) did not differ from the controls [7.0 (±1.5) years] and 64% respectively. The mean 25-hydroxy vitamin D level for cases [22.6 (±7.9) ng/mL, (range 10–38 ng/mL)] was significantly lower than that of controls [29.1 (± 7.5) ng/mL, (range 15–46 ng/mL)] (p = 0.009). More cases (11/28, 39%) were vitamin D insufficient compared to controls (2/17, 11.8%, OR = 4.85, 95% CI = 0.92–25.5). All DXA scan results were consistent with normal bony mineralization for age (z-score > −2). The mean total body z-score for cases [0.6 (±0.9)] did not differ significantly from controls [0.9 (±0.9)] (p = 0.25). Conclusions: Mean serum vitamin D levels are significantly lower in African American children with fractures than matched controls. Future analyses will incorporate measurements of calcium and vitamin D intake, physical activity, sun exposure, body mass index and genetic analysis. Vitamin D insufficiency may play a previously unrecognized role in childhood fractures. doi:10.1016/j.bone.2009.04.156
PF-11 Malignant infantile osteopetro-rickets: The paradox of plenty A. Shalash, J. Rajah Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates Objective: The aim of this case report is to highlight: 1) the rare paradoxical presence of rickets in children with osteopetrosis, with its attendant complications. 2) that MIOPR is a medical emergency. Methods: A 3 month infant presented to the orthopedic department with a fracture of the upper third of the R femur. The child was in a cast and in traction. Parents were consanguineous (1st cousins) from Pakistan. Neonatal records revealed that he was investigated for thrombocytopenia. Weight and height measurements were on the 3rd centile. Clinical exam revealed, frontal bossing, widened wrists, roving nystagmus with pale optic disks and 4–5 cm hepatosplenomegaly. Results: Skeletal survey revealed osteopetrosis and rickets as well as the fracture femur. CT scan and MRI showed narrowing at the optic foramina. ALP was 1450 IU/L. Calcium was 2 mmol/L and phosphorus 0.69 mmol/L. Intact PTH was 29.1 pmol/L and 25 hydroxy vit D 14 nmol/L. Treatment consisted of calcium, calcitriol, ergocalciferol and interferon gamma. Conclusions: Unless early diagnosis is made and therapy started, these children die of infection or bleeding (encroachment of marrow space) or get permanent disability (blindness and deafness from compression of the optic and auditory foraminae and nasal obstruction from thickening of nasal bones). Rickets develops paradoxically when the Ca × PO4 product is decreased. Even though total body Ca is increased, it remains “trapped” in bone because of osteoclast dysfunction. Rickets further complicates the picture by promoting fractures, causing further irritability and poor feeding. Osteopetro-rickets may also attenuate the effectiveness of bone marrow transplantation as the new osteoclasts are unable to resorb bone in osteoid. doi:10.1016/j.bone.2009.04.157
PF-12 Multiple bone fractures in children — Environmental determinations A. Rusinska, D. Chlebna-Sokol, I. Michalus, A.M. Prochowska Department of Paediatric Propedeutics and Bone Metabolic Diseases, Medical University of Lodz, Lodz, Poland
S99
Aim: The aim of the study was the analysis of the relationships between selected environmental factors and bone fractures in children. Patients and methods: The study comprised 112 children aged 5–17 years, 81 patients with history multiple bone fractures and 31 healthy patients in control group. In all children densitometric examination of the skeleton with DXA method at total body and spine was taken. Moreover questionnaire examination taking into consideration the environmental factors which are probably connected with bone fractures was carried out. Results: In examined group more children than in controls were inhabitants (90 v. 78%, p < 0.05). The mean fracture number was higher in patients subjected to tobacco smoking (5.3 v. 3.3, p < 0.05). There was no observed relationship between mean time of sunlight exposure or number of children in family and fractures. Fathers of children with fractures predominantly have a vocational education (47%), in control group the most often was mean technical education (35%); there was negative correlation between the father's education and the number of fracture (R = − 0.29, p < 0.05). There was an observed significant relationship between the time of children school physical education and bone mineral density (R = 0.27 i 0.22, p < 0.05). Moreover, there was a negative correlation between the time of physical home activity and fracture number (R = − 0.26, p < 0.05). Conclusions: Multiple bone fractures in children may be also determined by environmental factors. Exposure to tobacco smoking, decreased physical activity and father's education seem to be connected with consecutive fractures in the developmental period. Acknowledgements: The study was partly financed by grant no. N407 063 32/2713. doi:10.1016/j.bone.2009.04.158
PF-13 Bone fractures in children — Evaluation of bone mineral density by dual energy X-ray absorptiometry and quantitative ultrasound D. Chlebna-Sokol, A. Rusinska, J. Golec, I. Michalus Department of Paediatric Propedeutics and Bone Metabolic Diseases, Medical University of Lodz, Lodz, Poland Aim: To evaluate the relationship between densitometry and quantitative ultrasound parameters of bone mineral density and fractures in children. Material and methods: The study involved 380 children aged 5–18 years, including 157 girls and 223 boys. In 10 children vertebral fractures were reported and 177 of them suffered from present or past long bones fractures. Dual energy X-ray absorptiometry and ultrasound examination of calcaneus was performed to assess bone mineral density. Results: The study revealed a statistically significant positive correlation between the results of bone mineralization obtained by densitometry and ultrasounds. The highest correlation coefficients were observed for Stiffness and BUA (broadband ultrasound attenuation) parameters and bone mineral density measured in total body. The analysis of the relationship between bone mineralization measurements and fractures revealed significantly lower mean Zscore parameters both in total body and spine in children with vertebral fractures. The values of ultrasound parameters in this group of patients were also lower, but the differences were not statistically significant. There were no significant differences observed between the patients with and without fractures of long bones for all bone mineralization results, even after detailed analysis in each age group was performed.