Trabecular and cortical bone separately assessed at radius with a new ultrasound device, in a young adult population with various physical activities

The aim was to evaluate a new ultrasound device in a young adult population and to assess its reproducibility via comparison to DXA measurements and geometrical measurements from high-resolution radiographs.Ninety-three subjects aged between 20 and 51 years were recruited and divided into four groups according to their gender and physical activity status: 22 male athletes, 19 male controls, 21 female athletes, and 31 female controls. Ultrasonic measurements were assessed by the prototype LD-100 (Oyo Electric Co., Kyoto, Japan) on the dominant distal radius. Attenuation in the radius (dB), cortical bone thickness (mm), radius thickness (mm), mass density of cancellous bone (mg/cm3), and elasticity (GPa) of cancellous bone were obtained. BMD was measured by DXA at the dominant distal radius. Radius images were obtained with a direct high-resolution digital X-ray device (BMA, D3A Medical Systems), and radius and cortical thicknesses were estimated using a specific software (ImageJ®, Bethesda, USA), in an area site-matched with LD-100.There was a significant positive correlation between site-matched BMD measurement and LD-100 parameters (p < 0.004), X-ray radius thickness, and LD-100 parameters except elasticity (p < 0.05, r > 0.32), X-ray cortical thickness and LD-100 attenuation and cortical thickness (p < 0.01). A significantly higher attenuation, cortical and radius thicknesses were found in athletes compared to controls (p < 0.05). The radius thickness measured on radiographs was significantly higher in athletes versus controls in both sexes, and cortical thickness was significantly higher in male athletes versus controls.These data suggest a positive influence of physical activity on bone cortical measurements. This study also confirmed the particular interest of bone assessment by ultrasound.