A new look at the sequential development of elbow-ossification centers in children

The pattern and sequence of ossification of the six secondary ossification centers around the elbow in the child were mainly derived from studies done >30 years ago. This series reexamined the sequence and pattern based on a cross-sectional study of the elbow radiographs of 1,577 Chinese children wi th elbow injuries; age range, from newborn to 17 years. The ratio of girls to boys was 1:2. Each child had a radiograph of the normal and the injured elbow giving a total of 3,154 radiographs. A percentile chart of ossificati on was constructed for each of the ossification centers in both sexes for e asy reference. No differences in the timing and ossification pattern were f ound between the right and left elbow or between the normal and injured elb ow in this study. The sequence of ossification in both boys and girls was f ound to be the same (i.e., thr capitulum first, followed by the radial head , medial epicondyle, olecranon, trochlea, and last, the lateral epicondyle) . The ages at which 50% of the girls were found to have positive radiologic ossification for each of these centers were ages 1, 5, 5, 9, 9, and 10 yea rs, respectively. In boys, with the exception of the capitulum, an average delay of 2 years was found in each of the ossification centers, although th e sequence remained similar.