Bone cement is a type of calcium phosphate. Calcium phosphate bone cement (CPC) is also called self-curing calcium phosphate. It is mainly composed of calcium phosphate powder and liquid phase (distilled water, solution, blood). When the two are mixed into a slurry, hydration and solidification occur in a short time and under certain physiological environment (37 degrees, 100% humidity), and the final product is the main component of bone —- hydroxyapatite. I. Characteristics: CPC has excellent bioactivity, biocompatibility, self-curing ability, and easy plasticity. History: In 1984, Galbert in France firstly used bone cement to treat vertebral hemangioma successfully, then it showed good advantages in repairing bone defects, fracture treatment, bone disease treatment, especially in the treatment of metastatic bone tumors, myeloma and other malignant lesions. III. Treatment mechanism: Metastatic bone tumor can cause pain, dysfunction and pathological fracture. In the treatment of bone cement filling, 1. the high temperature generated during the polymerization of bone cement has a permanent ablative effect on the destruction of tumor cells and nociceptive nerve endings. 2. the injection of bone cement can improve the biomechanical properties of bone, fix fiber fractures, reduce the small displacement of bone fractures, eliminate the extrusion and friction between tissues, and reduce the stimulation of nerve endings. 3. the bone cement blocks the blood supply to the local tissues, which has a positive effect on tumor cells and nociceptive nerve endings. of blood supply to tumor cells and nociceptive endings. Therefore, bone cement filling has good pain relief effect on metastatic bone tumor. Advantages compared with conventional radiotherapy, surgical treatment and internal fixation: less traumatic, faster onset of effect, wide indications, less complications, accurate localization under CT guidance, can kill most of the tumor cells, and easy to be accepted by patients with advanced disease. V. Instruments and drugs: The instruments were a full set of Murphy quick pvp instruments from COOK, including: 11G or 13G, 15.0cm long head-end triangular prismatic bone penetration needle and 10ml syringe or domestic stainless steel pressure syringe; the bone cement was a set of bone cement provided by Tianjin Synthetic Materials, including polymethyl methacrylate (PMMA) powder and liquid monomer. VI. Preoperative preparation: All patients should have routine X-ray plain film, blood routine and three blood coagulation examinations before surgery. A thin layer CT examination of 2 mm thickness should be performed at the lesion site to understand the extent and scope of the osteolytic lesion of the vertebral body, the involvement of the vertebral arch, the integrity of the bone cortex and the involvement of the intervertebral foramen and spinal canal, and to master the location of the needle entry point. The patient is placed in the prone position, and markers are placed on the body surface of the preoperative CT site according to the preoperative CT, and the vertebral body is scanned after using 2-3 mm layers to design the puncture route, and the distance and angle of needle entry are measured and marked. 2. The chest and hip are padded with pillows to reduce compression, the head is padded, and the elbow and knee joints are lowered. 3. The whole puncture process was carried out in steps under the guidance of CT, and the vertebral root on the healthy side was used as a reference for complete destruction, so that the tip of the puncture needle reached the anterior part of the lesion and the direction of the needle tip was adjusted in time. 4. PMMA powder and liquid monomer were prepared in the ratio of 20g:10ml. The newly configured bone cement is thin, at this time, use a disposable pressure syringe to extract 4-10ml and put it into the stainless steel tube rotary pressure syringe. When the bone cement is in the shape of toothpaste, 1-2 ml is injected into the vertebral root, and the needle is withdrawn while injecting from the front to the back, and the bone puncture needle is withdrawn to the bone cortex when the injection is completed, and the needle core is inserted and the needle is withdrawn after rotating the puncture needle, and local pressure is applied to stop bleeding. Then CT scan was performed to observe the distribution of bone cement and whether there was spillage. Apply antibiotics for 3-5 days after the operation for 4-6 hours in bed. Complications: There are two main types of complications: 1) inflammatory reaction caused by the polymerization of bone cement, resulting in fever and pain that can be relieved by anti-inflammatory treatment and symptomatic treatment 3-5 days after surgery; 2) leakage of bone cement into the surrounding vertebral body, due to compression of the spinal cord and nerve roots, with clinical manifestations of nerve root pain and spinal cord compression. For neuralgia, local infiltrative injection with anhydrous alcohol is available; for persistent nerve root pain, surgical removal of the leaking cement is required. Bone cement filling is a minimally invasive treatment that