Comparison of Three Methods of Assessing the Bone Age in Tibetan Children and the Features of Their Skeletal Maturity

  Objective  The aim of this study is to evaluate which of the three methods of assessing the bone age (BA), Greulich-Pyle (GP) atlas, Tanner-Whitehouse3 (TW3) and Chinese Hand Wrist Standard TW-China05, is most appropriate for Tibetan children, and to further investigate the BA characteristics of modern Tibetan children.

  Methods  Radiographs of the left hand of Tibetan children aged 4 to 18 years who presented with trauma to Tibet Autonomous Region People's Hospital between September 2013 and November 2019 were retrospectively collected. BAs of these radiographs were analyzed by two experienced reviewers based on the GP atlas who came from Peking Union Medical College Hospital. A previously reported artificial-intelligence (AI) BA system was used for the TW3(including TW3-RUS and TW3-Carpal) and TW-China05 method. The Pearson correlation method was used to analyze the correlation between calendar age and BA determined by GP atlas, TW3 and TW-China05 methods.

  Results  There were 305 Tibetan children (209 boys and 96 girls) with a mean calendar age of 11.22±4.81 years included in this study. Pearson correlation analysis showed that the BAs measured by the GP atlas, TW3-RUS, TW3-Carpal and TW-China05 methods are highly correlated with the calendar ages of Tibetan children, and the GP atlas has the strongest correlation (r=0.961), followed by TW3-RUS method (r=0.941), TW-China05 method (r=0.937), and TW3-Carpal method(r=0.895). From 4- to 10-year-old, the BAs of all Tibetan boys and girls were smaller than their calendar age with a difference degrees; subsequently, BAs showed a tendency of catch-up during puberty, but still lagging behind calendar ages from 16- to 18-years old.

  Conclusions  Compared with the TW3 and TW-China05 methods, GP atlas may be the most accurate method of BA assessment for Tibetan children. BAs of modern Tibetan children shows catch-up trend during adolescence, but still lag behind calendar ages by the age of 18.