Among malignant bone tumors, osteosarcoma is the most common, which occurs in adolescents, and 80%~90% of osteosarcoma occurs in the metaphyses of long bones of the limbs, especially the distal femur, proximal tibia and proximal humerus. In the past, due to the limited diagnosis and treatment technology, the 5-year survival rate of osteosarcoma was low, the amputation rate was high, and the postoperative functional recovery was poor, which brought great pain to patients and their families. In recent years, with the continuous updating of diagnosis and treatment concepts, the prognosis of bone tumors has greatly improved. Important breakthrough: neoadjuvant chemotherapy can reduce the scope of the tumor and make the tumor boundary more precise In the past, most of the surgical methods for bone sarcoma were amputation, and the 5-year survival rate after surgery was less than 20%, and the main cause of death was lung metastasis. The emergence of the concept of neoadjuvant chemotherapy is an important breakthrough in the history of osteosarcoma treatment. The so-called neoadjuvant chemotherapy is systemic chemotherapy before performing surgery, and then continue chemotherapy after surgery. It can narrow down the scope of the tumor and make the tumor boundary more exact, which is conducive to the complete resection of the tumor and increase the 5-year survival rate from less than 20% to 60%~70% after surgery. Improvement of prognosis: limb preserving surgery makes many osteosarcoma patients free from amputation At the same time, the emergence of limb preserving surgical modalities such as autologous or allogeneic bone joint transplantation, tumor segmental bone inactivation implantation, artificial prosthesis replacement, etc., also provides a broad prospect for the treatment of osteosarcoma, which makes many osteosarcoma patients free from amputation, and the quality of life is greatly improved. For example, bone inactivation and replantation of tumor segment is to make the tumor segment lose its biological activity through chemical, high temperature, freezing and other methods after it is taken down, and then replant it back to the original place in order to preserve the function of limb. In conclusion, from simple chemotherapy to neoadjuvant chemotherapy, changing amputation to limb preservation has gradually become one of the new trends in the diagnosis and treatment of bone tumors, which has saved many patients with osteosarcoma from amputation and greatly improved their quality of life.