Periosteum is a fibrous connective tissue fascia, a periosteum that surrounds the outside of the bone and is rich in blood vessels and nerves, so damage to the periosteum often leads to local hematoma and severe pain, which usually takes about 3 weeks to repair, quite fast compared to the bone, because it has abundant blood circulation and also a loose tissue structure. Damage to the periosteum can be caused by a variety of reasons, and if it is caused by injury, it takes about two weeks for the hematoma to evolve mechanically and for the corresponding local repair to take place, which generally takes about 3 weeks to recover. If the damage is due to inflammation, the periosteum will gradually recover after the inflammation is removed, which usually takes 2-3 weeks. In some cases, periosteal damage is caused by tumors, which can lead to a periosteal reaction, a laminar proliferation of bone and periosteum, and in this case, surgery is usually required, depending on the nature and severity of the tumor to see if it can recover.