Skeletal age determinations in children of European and African descent: Applicability of the Greulich and Pyle standards

This study assesses the value of the Greulich and Pyle method in determinin g the skeletal ages of healthy American children of European and African de scent born after the year 1980. The hand and wrist radiographs of 534 child ren (265 boys, 269 girls; 260 European-Americans [EA], 274 African-American s [AA]), acres 0 to 19 y, were analyzed by two experienced pediatric radiol ogists blinded to the chronological age of the subjects. A difference score was calculated for each subject by subtracting chronological age from the mean bone ages scores provided by the two raters. One group t-tests were pe rformed to verify the hypothesis that the mean difference score was equal t o zero. Skeletal age determinations by the two radiologists showed a high d egree of agreement by intraclass correlation coefficient (r = 0.994). The r ange of values for differences in skeletal and chronological ages was very wide, indicating great individual variability. Comparisons between skeletal and chronological age only reached statistical significance in EA prepuber tal girls, whose skeletal ages were delayed, on average, by three months (t = -2.9; p = 0.005). Mean difference between skeletal and chronological acr e in prepubertal children of African descent was 0.09 +/- 0.66 y, while tha t in children of European descent was -0.17 +/- 0.67 y; (t = 3.13; p = 0.00 19). On average, the bone ages of 10% of all prepubertal AA children were 2 SD above the normative data in the Greulich and Pyle atlas, while the bone ages of 8% of all prepubertal EA children were 2 SD below. In contrast to the racial differences observed in prepubertal children, EA postpubertal ma les had significantly greater values for bone age than AA postpubertal male s (t = 2.03; p = 0.05). In conclusion, variations in skeletal maturation in prepubertal children are greater than those reflected in the Greulich and Pyle atlas; prepubertal American children of European descent have signific antly delayed skeletal maturation when compared with those of African desce nt; and, postpubertal EA males have significantly advanced skeletal maturat ion when compared with postpubertal AA males. New standards are needed to m ake clinical decisions that require reliable bone ages and to accurately re present a multiethnic pediatric population.