Radial tuberosity subluxation in children is normal on x-ray and no abnormality can be found. The reason that the radial tuberosity is dislocated but cannot be found on film is related to the developmental characteristics of the bones of children. The radial tuberosity is at the upper end of the radius, called the proximal end, and there is an epiphysis of the radial tuberosity, and the epiphysis is cartilage. The cartilage is not visible on the X-ray, that is, the X-ray does not illuminate. Therefore, even if a little bit of cartilage is removed, it is normal because it does not show up on the X-ray. However, even if a radial tuberosity subluxation has occurred, in some cases, doctors may ask some patients to undergo an X-ray. This is because the medical history of the injury is not clear. For example, if parents come home and find that their child’s arm is not moving well and they go to the hospital, the doctor will naturally ask how the child was injured, and many parents will say they are not sure because they did not see him at work, and then the doctor will request an x-ray to rule out other lesions, such as the presence of a fracture or a more serious dislocation.