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J Sports Sci ; : 1-8, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29912627


Given the lack of relevant data, the aim of this study was to examine femur cortical and trabecular bone in female and male professional ballet dancers. 40 professional ballet dancers and 40 sex- and age-matched non-exercising controls volunteered. Femoral bone density was scanned by dual-energy X-ray absorptiometry (DXA) scan. A 3D-DXA software was used to analyse trabecular and cortical bone. Anthropometry, maturation (Tanner staging), menstrual parameters (age at menarche and primary amenorrhea), energy availability and nutritional analysis (3-day record) were also assessed.Compared to non-exercising participants, dancers exhibited significantly higher volumetric density for integral, cortical and trabecular bone, and thicker cortex at the femur. Ballet dancers demonstrated lower body weight compared to controls (p < 0.01). Female dancers had their menarche later than controls, and the prevalence of primary amenorrhea were significantly higher in dancers than controls (p < 0.01). Dancer's energy availability was below the normal range (<30 kcal/kgFFM/day). Despite the presence of certain osteoporosis risk factors such as low energy availability, primary amenorrhoea and lower body weight, professional ballet dancers revealed higher bone density for both cortical and trabecular bone compartments compared to controls.

J Clin Densitom ; 21(4): 480-484, 2018 Oct - Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28648836


High bone mass (HBM), a rare phenotype, can be detected by dual-energy X-ray absorptiometry (DXA) scanning. Measurements with peripheral quantitative computed tomography at the tibia have found increased trabecular bone mineral density and changes in cortical bone density and structure, all of which lead to increased bone strength. However, no studies on cortical and trabecular bone have been performed at the femur. The recently developed 3-dimensional (3D)-DXA software algorithm quantifies the trabecular and cortical volumetric bone mineral density (vBMD) and the anatomical distribution of cortical thickness using routine hip DXA scans. We analyzed the femurs of 15 women with HBM and 15 controls from the Barcelona Osteoporosis (BARCOS) cohort using the 3D-DXA technique. The mean vBMD of proximal femur was 29.7% higher in HBM cases than in controls for the integral bone, 41.3% higher for the trabecular bone, and 7.3% higher for the cortical bone (p < 0.001). No differences in bone size were detected between cases and controls. Patients with HBM had a thicker cortex and higher trabecular and cortical vBMDs, as measured by 3D-DXA at the femur and compared to controls; bone size was similar in both groups. To the best of our knowledge, this is the first description of trabecular and cortical characteristics of the hip in patients with HBM.

IEEE Trans Med Imaging ; 36(1): 27-39, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27448343


The 3D distribution of the cortical and trabecular bone mass in the proximal femur is a critical component in determining fracture resistance that is not taken into account in clinical routine Dual-energy X-ray Absorptiometry (DXA) examination. In this paper, a statistical shape and appearance model together with a 3D-2D registration approach are used to model the femoral shape and bone density distribution in 3D from an anteroposterior DXA projection. A model-based algorithm is subsequently used to segment the cortex and build a 3D map of the cortical thickness and density. Measurements characterising the geometry and density distribution were computed for various regions of interest in both cortical and trabecular compartments. Models and measurements provided by the "3D-DXA" software algorithm were evaluated using a database of 157 study subjects, by comparing 3D-DXA analyses (using DXA scanners from three manufacturers) with measurements performed by Quantitative Computed Tomography (QCT). The mean point-to-surface distance between 3D-DXA and QCT femoral shapes was 0.93 mm. The mean absolute error between cortical thickness and density estimates measured by 3D-DXA and QCT was 0.33 mm and 72 mg/cm3. Correlation coefficients (R) between the 3D-DXA and QCT measurements were 0.86, 0.93, and 0.95 for the volumetric bone mineral density at the trabecular, cortical, and integral compartments respectively, and 0.91 for the mean cortical thickness. 3D-DXA provides a detailed analysis of the proximal femur, including a separate assessment of the cortical layer and trabecular macrostructure, which could potentially improve osteoporosis management while maintaining DXA as the standard routine modality.

Absorciometria de Fóton , Densidade Óssea , Fêmur , Humanos , Imagem Tridimensional , Tomografia Computadorizada por Raios X