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. II. History: In 1984, Galbert in France first used bone cement to treat vertebral hemangioma successfully, and then 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 tiny 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 of 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 trauma, 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 in advanced stage. V. Instruments and drugs: The instruments were a full set of Murphyquick 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. CT thin layer examination of 2mm layer thickness should be performed at the lesion site to understand the degree and scope of 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. VII. Surgical operation: The patient is placed in prone position, markers are placed on the body surface of the pre-piercing site according to the preoperative CT, the vertebral body is scanned after using 2-3 mm layers, the puncture route is designed, 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 towel is routinely disinfected and laid, and soft tissue is performed at the puncture site with 1% lidocaine in the direction of the vertebral roots. The whole puncture process was carried out in steps under the guidance of CT, and the healthy vertebral root 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 bone cement just configured is in thin state, at this time, use disposable pressure syringe, extract 4-10ml, and fill into stainless tube rotary pressure syringe. When the bone cement is in the shape of toothpaste, 1-2ml 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 finished, and the needle core is inserted and the puncture needle is withdrawn after rotating, 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. Postoperative bed rest for 4-6 hours apply antibiotics for 3-5 days. Complications: The main complications are two types: 1. inflammatory reaction caused by heat production of bone cement polymerization, 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 vertebral body around the spinal cord and nerve root compression, clinical manifestations of nerve root pain and spinal cord compression. Neuralgia can be injected by local infiltration of anhydrous alcohol, and persistent nerve root pain requires surgical removal of the leaking cement. Bone cement filling is a minimally invasive treatment.