Congenital dislocation of the radial tuberosity is rare, with 11 cases first reported by McFarland in 1936. The cause of the dislocation is unknown and may be related to genetic factors. The main manifestation of this disease is bilateral asymmetry of the elbow, sometimes with popping or limited movement when extending or flexing the elbow joint. The direction of ulnar bending is related to the type of dislocation, such as anterior dislocation of the radial tuberosity, in which the ulna projects anteriorly; posterior dislocation of the radial tuberosity, in which the ulna projects posteriorly; and lateral dislocation, in which the ulna projects laterally. When the radial tuberosity is dislocated anteriorly, the range of elbow flexion becomes smaller and the dislocated radial tuberosity can be found in the elbow fossa; when the radial tuberosity is dislocated posteriorly, the elbow joint cannot be completely straightened and the protruding radial tuberosity can be found behind the elbow. x-ray shows that the longitudinal axis of the radial stem does not cross the humeral head on the lateral view of the elbow joint, the radial head is dome-shaped, the radial neck forms an articulation with the humeral tuberosity, and indentation can occur at the contact site. No history of trauma, the dislocated radial tuberosity can be palpated at the elbow, and the diagnosis can be confirmed when the X-ray shows the radial tuberosity dislocation. It needs to be differentiated from traumatic radial tuberosity dislocation. The diagnosis of traumatic radial subluxation is made by Monteggia fracture, radial neck fracture, stretched elbow, and other injuries. Flexion of the ulna is not an exclusive feature of congenital radial tuberosity and can occur in undisplaced traumatic radial tuberosity. In congenital radial tuberosity, the humeral tuberosity is small and the radial tuberosity is oval in shape. If there is ossification of the soft tissue around the radial tuberosity, it is suggested that it is an unreset traumatic radial tuberosity dislocation. 1.Non-surgical treatment The dislocation of radial tuberosity in infancy and early childhood can be attempted to be closed and repositioned, and the posterior dislocation of radial tuberosity can be fixed in forearm rotation and elbow extension position, while the anterior dislocation of radial tuberosity can be fixed in elbow flexion position. After repositioning, plaster is fixed for 4 to 6 weeks. However, the treatment effect is often disappointing. 2.Surgical treatment For those who are 3 years old, the radial tuberosity is repositioned by incision, shortening osteotomy and circumferential ligament reconstruction in the middle of the radial stem at the attachment point of the anterior circular muscle. The radial tuberosity was temporarily fixed to the humeral tuberosity using a Kirschner pin. The posterior piece of the upper elbow was fixed in a cast for 6 weeks, then the Kirschner pin was removed and exercise of the elbow joint mobility was started, and the elbow joint brace was fixed for three months. However, there is a possibility of recurrence. For larger children with radial tuberosity dislocation, radial tuberosity resection can be considered by adolescence.