III. Treatment methods
Surgery is currently the most effective treatment for giant cell tumor of bone, but giant cell tumor of bone is prone to recurrence after surgery. According to the degree of anatomical structure and functional destruction of bone and joint, surgery is divided into three levels: intra-lesion scraping, segmental resection and amputation. Intra-lesion scraping includes scraping bone grafting and scraping bone cement filling; lumpectomy includes simple lumpectomy, lumpectomy autologous bone grafting, lumpectomy allogeneic bone grafting, lumpectomy inactivated replantation, joint fusion and artificial joint replacement.
The principle of surgery is to completely remove the tumor while preserving the normal structure and function of the bone and joint as much as possible. Because the proliferation rate of giant cell tumor cells is not high and they are not sensitive to chemotherapy, the efficacy is often unsatisfactory, and chemotherapy is only used to control tumor development before surgery for patients with lung metastases. Radiation therapy is also only applicable to patients whose tumors are not surgically resectable due to their special growth sites, and the sensitivity of this tumor to radiation therapy is also very low, and the malignancy rate of radiation therapy is high. Most of the cases can be cured with timely and appropriate treatment, and the joint function can be preserved satisfactorily.
1. Lesion scraping and bone grafting (Attachment 3 see previous section): Preoperative balloon tourniquet is tied to avoid blood expulsion operation, firstly, the tumor is scraped thoroughly by opening the window. Make a longitudinal arc-shaped incision centered on the tumor site, with both ends exceeding the upper and lower poles of the tumor. After dissecting the deep fascia, the periosteum is incised in the direction of the incision and subperiosteal dissection is performed. The junction between the normal bone and the tumor is found, and the hole is drilled continuously with a bone drill, and then a window is opened along the bone hole with a bone knife or bone chisel (usually the site with severe bone destruction and non-weight-bearing bone area).
The size of the window depends on the extent of tumor invasion, and it is appropriate to scrape away the tumor under direct vision. After the lesion is fully exposed, the tumor tissue in the bone cavity is first scraped off with a scraper, and then the bone wall, interval, sclerotic bone and its residual lesion are removed from the upper wall, inner wall and lower wall in three directions with a bone knife until the normal bone is exposed, and if necessary, a thin layer of cancellous bone can be removed to reduce the retention of tumor cells around the tumor. In the process of excision and scraping, care should be taken not to damage the articular cartilage and strive to preserve the normal articular surface.
The correct use of adjuvant methods combined with modern extensive scraping techniques is an important means to reduce the recurrence rate. The inactivating agents used clinically are: carbolic acid, liquid nitrogen, 95% alcohol, zinc chloride, phenol, hydrogen phosphate, hydrogen peroxide, etc. Recently, argon electric knife cautery and microwave irradiation have also been put into use.
Finally, the residual bone graft is used to fill the lesion with autologous and/or allogeneic bone and compress it in order to restore the strength of the subchondral bone of the joint in as short a time as possible. If the lesion is small, autologous bone grafting can solve the problem; if the bone defect is too large for autologous bone to meet the filling needs, combined autologous and allogeneic bone implantation can be used, in which case the autologous bone should be placed directly in the subchondral area of the articulation, and the allogeneic bone should be placed in the area that is not important for bone repair. Regular postoperative film review should be taken to determine the weight-bearing time according to the bone repair situation.
2. Focal scraping and bone grafting + bone cement filling (Attachment 4): The surgical opening and inactivation methods are the same as focal scraping and bone grafting, with the difference that the residual cavity is repaired with bone grafting + bone cement filling. It is mainly used in cases where the residual cavity is large and the scraped edge reveals part of the articular cartilage, mostly in the lower femur and upper tibia with osteomegaloblastic tumors. To maintain the stability of the articular surface and the survival of the articular cartilage, autologous iliac bone is taken and approximately 10 mm thick cancellous bone is implanted on the exposed cartilage surface before cement filling.
Bone cement (methyl methacrylate) can be used as a bone filler, a support, and an aid in tumor killing by the toxicity of its monomer and the heat generated during polymerization. The recurrence rate was reported to be significantly lower after scraping of the lesion and filling the residual cavity with bone cement. Figure 5 shows a 5-year follow-up X-ray after scraping and cement filling of the distal femur for giant cell tumor with no tumor recurrence.
Figure 4: Osteoblastoma of the distal femur, after scraping and cement filling of the lesion.
Figure 5: X-ray 5 years after resection of giant cell tumor of the distal femur and cement filling.
3. Segmental resection + arthroplasty: For giant cell tumor that invades most of the bone ends and the joint surface has collapsed, or the pathology has been changed by fibrosarcoma, segmental resection plus arthroplasty can be used. Other indications include.
①The systemic condition and local soft tissue conditions allow, the main nerves and blood vessels are not involved, extensive resection can be achieved, and the expected local recurrence rate is not higher than that of amputation;
②No metastatic lesions or metastatic lesions can be cured;
③The patient has a strong desire for limb preservation and financial ability;
④Postoperative function is better than that of prosthesis.
Contraindications for surgery are.
①Tumor invasion is extensive, and important nerves and blood vessels are involved and cannot be completely removed;
②Local and systemic infection;
③Poor general condition or local skin and soft tissue condition, which may make it difficult to tolerate the surgery or may lead to difficulty in closing the incision and skin and soft tissue necrosis after surgery;
④In advanced stage of tumor, the patient’s life expectancy is short and the patient has no strong desire to preserve the limb.
Bone tumor prosthesis replacement is different from general artificial joint replacement, the design, material performance and fixation technology of tumor prosthesis are more demanding. The postoperative complications of prosthesis replacement mainly include recurrence, infection, prosthesis loosening and prosthesis fracture. Infection is the most serious of the postoperative complications, often leading to catastrophic consequences, and should be prevented.