The elbow has been captured on the lateral view of the forearm radiograph and the secondary ossification center of the olecranon has been marked with a border (dotted line). The patient is a male aged 12. According to the Sauvegrain and Dimйglio method the olecranon ossification stage with a rectangular shape is 6. This stage was found to be a cutoff point in association with disturbed bone union after ESIN of forearm shaft fracture.