Elbow hyperextension of 15 degrees refers to an angle of 15 degrees to the dorsal side when the elbow joint is fully extended. It may be caused by fracture, ligament and soft tissue laxity, etc. Different causes, different treatments, the main treatments are surgical treatment, general treatment and so on. 1. Supracondylar humerus fracture: the elbow joint hyperextension that occurs after the fracture has healed abnormally can generally be treated with surgical osteotomy to restore the fracture alignment and alignment of the distal end of the humerus, which can alleviate and correct the state of hyperextension. 2. Ligament and soft tissue laxity: it belongs to congenital variation, no special treatment is needed, it will not cause joint function disorder, nor will it cause arthritis in the later stage, but it should be strengthened to take care of it, and carry out limb function exercise more often. It is recommended that patients with 15 degrees of elbow hyperextension should go to the hospital in time and follow the doctor’s instructions for standardized treatment.