RUS skeletal maturity of children in Beijing

Background: RUS (radius-ulna-short bones) maturity of children has been estimated in two provinces in China, but not in the capital. In order to obtain a clearer picture of skeletal maturity in China, it is indispensable to include children from Beijing in the study. Aim: The aims of this study were three-fold: (1) to establish RUS skeletal maturity of children in Beijing, (2) to compare RUS skeletal maturity in Beijing with the Tanner Whitehouse 3 (TW3) standard and the Tokyo standard, and (3) to examine regional variation in skeletal maturity in China. Methods: Hand and wrist radiographs of 631 boys and 642 girls, aged 6-18, were obtained in Beijing in 1997, and their RUS skeletal maturity was estimated using the TW3 method. Results: RUS maturity of the Beijing children was very similar to the TW3 standard until the age of 10 years in the girls, and the age of 12 years in the boys. The girls attained full maturity at 15 years of age, matching the TW3 and Tokyo standards, while the boys reached full maturity at the age of 16 years, as in Tokyo boys, but 1 year earlier than the TW3 standards. Beijing children showed progressively more rapid bone maturation than the Harbin and Changsha children, and attained full maturation 1 year earlier, in both girls and boys. Conclusion: The RUS maturity of the Beijing children was comparable with that of Tokyo children, except for the boys between 11 and 13 years. Variability of the RUS maturation among the Chinese children was greater than that found among the TW3, Tokyo and Beijing children.