The cause of sternal fractures in children is unknown and is difficult to detect during normal obstetrical examinations, and can only be observed and treated after birth. If parents find a U-shaped sternal fracture in their baby, they should seek immediate medical attention. Because sternal fractures get worse with age, the best time to operate is during the neonatal period. The following methods of examination for sternal fracture are available: 1.X-ray – plain film: fluoroscopy, radiographs (radiographic methods: PA position/AP position; lateral position; anterior arch position; lateral horizontal projection; respiratory gas phase contrast; stratification; bronchography ……) body layer, CR, DR 2.Other imaging means: PET, SPECT, etc. 3.The role and limitation of chest X-ray examination. Insufficient resolution, referring to the contrast resolution and overlap phenomenon, insufficient sensitivity, some lesions such as the congestive phase of lobar pneumonia, despite the obvious clinical symptoms, but the X-ray does not show abnormalities; insufficient specificity: similar performance of different diseases; different performance of the same disease (same disease, different disease, same shadow). The clinical manifestations of children often include paradoxical breathing, cyanosis, dyspnea and recurrent respiratory infections. Physical examination reveals soft tissue fissures in the upper, lower or all of the sternal region and palpable vascular pulsations. central line defects in the upper abdominal wall, pericardial defects adjacent to the diaphragm and various types of cardiac malformations can be seen in Cantrell syndrome.