1, Data and Methods 1.1 General Data There were 24 cases in this group, 15 male and 9 female, aged 21-68 years old, average 53 years old. Among them, there were 2 cases of congenital spinal deformity, 9 cases of tuberculous kyphosis, 8 cases of old traumatic kyphosis, and 5 cases of osteoporotic kyphosis in the elderly. Clinical manifestations included low back pain, sedentary difficulties, intercostal neuralgia, impairment of lower limb nerves and bladder sphincter function, etc. According to the Frankel grading of spinal nerve function, there were 14 cases of grade E, 8 cases of grade D and 2 cases of grade C. The apex of the kyphosis was located at the T-axis of the spine, which was the most important point in the spinal cord. The vertex of kyphosis was located in T115, T1210, L17 and L22 cases respectively. The preoperative Cobb’s angle of kyphosis ranged from 42° to 90°, with an average of 82°. 1.2 Surgical method General anesthesia, prone position, posterior median approach, first determine the vertebral body at the apex of the kyphosis, reveal the spinous processes of the apex vertebrae and the neighboring upper and lower vertebral bodies, bilateral vertebral plates, articular eminences and transverse processes, and then place pedicle screws of the appropriate length into the bilateral pedicles of the neighboring upper and lower vertebral bodies in the positioning of the C-arm X-ray machine. According to the preoperative design of the osteotomy range and angle, the spinous process of the parietal vertebrae, the adjacent supraspinous ligament and interspinous ligament were resected, and the parietal vertebral plate and ligamentum flavum were resected with a bone cutter and vertebral plate biting forceps, as well as the small articular eminences of both sides. If the parietal vertebrae were in the thoracic spine, the small head of the ribs and a small part of the proximal ribs were resected at the same time, so that the dural membrane and the nerve roots were exposed and protected. The spinal cord and nerve roots are gently pulled to the side, the transverse processes are cut off at the root of the transverse processes on both sides, the vertebral body is peeled off under the periosteum in front of the vertebral body along the arch root, the large blood vessels on the front side of the vertebral body are pushed forward in the anterior longitudinal ligament rounds, the large blood vessels on the anterior side of the vertebral body are pushed forward, and protected by the S-type dissector, and then the arch roots are excised, the posterior column and the middle column of the spinal column is largely amputated, and the vertebral body only is left in front of the vertebral body, and the provisional pedicle nail fixation round rods can be installed in the side at this time first. In this case, a temporary pedicle fixation round rod can be installed on one side first, and the osteotomy operation can be done on the other side. Be careful to make the width and depth of the osteotomy consistent on both sides to prevent extrusion of the spinal cord and nerve roots during orthopedic treatment. After the completion of osteotomy on both sides, the upper and lower spinous processes of the osteotomized area are pressed forward to close the osteotomized section, observe the effect of kyphosis correction, restore the original physiological curvature of the kyphosis area, and design the curvature of the round rods in order, connect them to the pedicle screws and tighten the top wire to lock the fixation device. Appropriate pressure should be applied between the sections before locking to facilitate osseous fusion. In this group, the internal fixation devices were all applied with the nail-rod system, fixing two vertebrae on the upper and lower sides (i.e., eight nails and two rods plus one transverse connecting rod). After fixation, if the deformity is corrected satisfactorily but the space left in the intervertebral space, autogenous bone particles can be taken in the intervertebral compression bone grafting. 1.3 Postoperative treatment After the operation, anti-infective, nutritive nerve and other medications were routinely given, methylprednisolone was applied for 3-5 days, and the drainage tube was removed within 24-48 hours. Patients should mainly rest in bed for 2 months after surgery, and can sit up or get out of bed to urinate and defecate under the protection of the support for 3 months after surgery, and insist on the functional exercise of lumbar and dorsal muscles after removing the stitches, and take X-rays regularly for review. 1.4 Criteria of efficacy: Excellent: the spine can be completely straightened and normal work can be resumed. Good: most of the kyphosis can be corrected, and the spine can be engaged in light work. Good: the kyphosis is mostly corrected, and the spine can be used for light work. Poor: the kyphosis was not corrected, or the deformity was corrected, but combined with spinal cord or nerve root compression, and the patient could not take care of himself/herself. Results: 24 cases in this group were followed up for 10 months to 5 years, with an average of 3.5 years. The treatment effect was excellent: 15 cases (62.5%), good: 7 cases (29.2%), acceptable: 2 cases (8.3%), excellent rate: 91.7%. The Cobb’s angle of kyphosis of all patients improved from an average of 82° before surgery to an average of 8.3° after surgery, with an average correction rate of 89.6%. Among them, the physiological curvature of the thoracolumbar spine was completely restored in 15 cases, and the appearance of the kyphosis was significantly improved in the remaining cases, with the curvature of the spinal canal sequence smoothed out, and the spinal nerve root pulling and compression relieved. Neurological function recovery after surgery: 2 cases of Frankel C grade were recovered to D grade, 5 cases of 8 cases of D grade were recovered to E grade, the other 3 cases were unchanged, and the rest of the cases remained at the preoperative E grade. The X-ray films were reviewed 8 to 12 months after the operation, which showed that the original osteotomy planes had undergone bony fusion, and the internal fixation system of nail rods was strong and reliable, and no complications such as loosening of the endoprosthesis, breakage, pseudoarthrosis and loss of corrective degree were found. 3, Discussion: Spinal kyphosis is a common spinal deformity, which not only affects the appearance, but also is often accompanied by neurological impairment, which seriously affects the patient’s life and ability to work. In normal people, the physiological kyphosis of thoracic spine is less than 50°, and the apex of kyphosis is at T6-8, which forms a balanced physiological arc with lumbar anterior kyphosis, and at this time, the sagittal plane gravity plumb line passes through C1-T1-T12 and S1, which maintains the optimal physiological curve and body balance [1]. Congenital spinal deformity, spinal trauma, tuberculosis and other diseases can lead to an increase in the angle of spinal kyphosis. When the kyphosis is greater than 60°, the deformity will continue to aggravate, and there will be much pain in the back, neurological dysfunction of the lower limbs, and even paraplegia, which generally requires corrective treatment. The significance of kyphosis surgery is to correct the deformity, restore the normal physiological curvature, relieve the nerve compression, stabilize the fusion of the spine, alleviate the local pain and improve the neurological function through the implementation of osteotomy shortening and straightening of the spine. The main surgical approaches are: anterior and posterior combined surgery, simple anterior surgery and simple posterior surgery. In the method of anterior or anterior-posterior combined osteotomy correction, it is clinically proven that: the operation takes a long time, bleeds a lot, has a big surgical injury, and has a big chance of occurrence of various kinds of complications accordingly, relatively speaking, the posterior spinal osteotomy orthopedic surgery has a small injury, few complications, and it can make the correction operation complete once while decompression is performed, and as long as the method is mastered appropriately, it seldom has a serious complication [2]. The main points of posterior osteotomy and orthopedic surgery include: exhaustive preoperative imaging evaluation and the development of a sound surgical plan, determining the site and range of osteotomy and selecting the fixation point for internal fixation through a detailed understanding of the deformed spinal structures and the corresponding spinal cord neural structures in the vertebral canal, which should be adequately exposed during the surgery, and maintaining a clear surgical field through anesthesia-controlled hypotension and subperiosteal dissection as well as good hemostasis. The entry point of the pedicle is carefully identified to ensure firm transpedicular fixation, with at least 2 segments above and below the osteotomy site to provide sufficiently firm fixation strength.