Ultrasound bone densitometry of the os calcis in children and adolescents.

The aim of the present investigation was to evaluate reference data and to examine whether there were weight-, height-, age-, and sex-related differences of the quantitative ultrasound bone parameters for healthy children and adolescents. A total of 3299 healthy Caucasian children and teenagers (1623 girls and 1676 boys), age range from 6-18 years (mean age 11.4 +/- 3.4 years for boys and mean age 11.5 +/- 3.3 years for girls) were examined by quantitative ultrasound densitometry (QUS) using the bone sonometer SAHARA (Hologic Inc., Waltham, MA, USA), a waterless, dry system. The parameters broadband ultrasound attenuation (BUA) [dB/MHz] and speed of sound (SOS) [m/second] were evaluated on the right heel in relation to age, sex, weight, and height. There is no correlation between the ultrasound bone parameter SOS and age, height, and weight. BUA increases with age, height, and weight. Significant differences in SOS and BUA between girls and boys were found to probably be caused by the different onset of growth phases and the onset of puberty. SOS and BUA are influenced by changes of bone mineral density. But BUA is dependent on bone size, too. In conclusion, ultrasound bone densitometry is a useful measuring method showing the physiological bone development in childhood and adolescence. The presented results can be used as reference data. Further studies in children with disorders influencing bone metabolism will show in what way various patterns of osteopenia in childhood can be detected.