Thoracolumbar kyphosis, commonly referred to as hunchback, is commonly caused by congenital vertebral developmental malformations, old tuberculosis of the spine, old trauma, ankylosing spondylitis and Hewman’s disease, etc. It has a long course and continues to progress, often leading to spinal cord compression and paraplegia, and can also lead to compensatory lumbar hyperlordosis due to the presence of kyphosis and lower back pain, and causes serious psychological disorders to patients, often requiring surgery to relieve nerve compression and It often requires surgery to relieve nerve compression and correct the deformity. Orthopedic spinal osteotomy is an effective treatment for thoracolumbar kyphosis, and there are currently three main surgical approaches, namely anterior, combined anterior and posterior, and posterior. The anterior approach alone can only decompress the nerve, and the orthopedic effect is poor; the combined anterior-posterior approach has a better orthopedic effect, but the surgery is traumatic, the complication rate is high, and the postoperative recovery time is long; the posterior osteotomy orthopedic surgery can obtain both nerve decompression and correction of the kyphosis, and has become the main surgical approach at present. In 1945, Smith-Peterson first applied posterior osteotomy to the surgical correction of posterior kyphosis in ankylosing spondylitis, which is accomplished by V-shaped osteotomy of the lumbar appendages and opening of the anterior column. This approach is an “anterior column lengthening” osteotomy. In the beginning, its application was limited by the use of large external forces to open the anterior structures, the lack of effective internal fixation, poor local stability, and the high incidence of complications such as spinal cord and large blood vessel injuries and pseudoarthrosis formation. In order to improve orthopedic efficiency and reduce the incidence of complications, many scholars have improved this procedure over the decades. One of the more widely used procedures is the multisegmental “V” osteotomy, also known as the Ponte osteotomy. This osteotomy only wedges the posterior accessory structures corresponding to the intervertebral space and closes the posterior osteotomy surface with varying degrees of opening of the anterior intervertebral space for orthopedic purposes. Although the orthosis of a single segment is only about 10o, a larger correction rate can be obtained by osteotomy and orthosis in multiple adjacent segments. In addition, the osteotomy method allows the correction of the kyphosis to be distributed over multiple segments, and the stress is more distributed, which is more conducive to the restoration of a smooth physiological curve in the sagittal plane of the spine. Therefore, this procedure is suitable for the treatment of rounded back deformities such as ankylosing spondylitis and Hewman’s disease. In 1985, Thomason reported the use of a wedge-shaped closed osteotomy technique of the vertebral body via the pedicle for the treatment of kyphosis due to ankylosing spondylitis. Because the osteotomy surface was enlarged to the anterior 1/3 of the vertebral body, it provided increased bony contact and stability with direct closure of the osteotomy surface after orthopedic treatment, resulting in a much higher fusion rate. Since then, this technique has been widely used to correct various types of kyphosis with good results. This method generally corrects about 40o of kyphosis, and further correction carries the risk of injury due to excessive shortening of the spinal cord. In some patients with kyphosis, the apex of the kyphosis is located at the level of the intervertebral space, and if a transperineal root osteotomy is performed for this type of deformity, the osteotomy site does not coincide with the apex of the kyphosis, thus reducing the surgical result. Therefore, by raising the level of the osteotomy to the level of the vertebral space at the apex and simultaneously removing the lower endplate of the vertebral body above the intervertebral space and the upper part of the vertebral body and part of the pedicle below, followed by closed orthosis, we have improved the efficiency of the osteotomy and orthosis and can achieve the same fusion rate. This procedure is referred to as a closed osteotomy through the synovial space. With this procedure, the deformity can be well corrected for posterior convexity angles up to 50o. For deformities with a kyphosis greater than 50o, if the apex of the kyphosis is a single vertebra or intervertebral space and the kyphosis does not exceed 90o, a posterior anterior elevation-posterior closed osteotomy is used. In this surgical approach, it is very important to sever the anterior longitudinal ligament. Since effective anterior release can be achieved after removal of the anterior longitudinal ligament, posterior closure based on anterior padding of the anterior half of the osteotomy gap can greatly improve the efficiency of the orthopedic procedure. According to our research data, in the traditional closed orthopedic procedure, 2.5o of posterior convexity can be corrected for every 1mm of osteotomy, while 6.2o of posterior convexity can be corrected for every 1mm of osteotomy using the anterior padding-posterior closed osteotomy orthopedic procedure. This surgical approach allows for effective correction of old traumatic kyphosis, mild to moderate old tuberculous kyphosis, and congenital kyphosis. For severe old tuberculous kyphosis and congenital kyphosis with an angle of more than 90o, it is a difficult surgical treatment for spinal deformity, and there was no ideal orthopedic solution in the past at home and abroad. Based on the method of localized anterior padding and posterior closure of the kyphosis, we have developed the technique of kyphosis segmental osteotomy and biaxial rotation orthopedics to complete the surgical correction of stiff deformities with kyphosis angles over 90o or even 140o. The advantages of this surgical method are: (1) in the braced state, the two ends of the osteotomy are rotated on their respective axes of rotation, which significantly reduces the obstruction to correction caused by closure of the ends and further overlapping of the ribs; (2) in the braced state, the spinal cord relaxes as the posterior convexity is corrected, but no significant shortening buildup occurs, thus avoiding the corresponding complications; (3) because the osteotomy ends are (3) Since the anterior side of the osteotomy is propped up under strict control, the correction of deformity will not cause excessive strain and injury to the large blood vessels; (4) In the propped-up state, the defect between the osteotomy ends of the spine is replaced by artificial vertebrae or titanium mesh, and the connection of the spine is natural and more in line with the physiological curve, which can preserve more thoracic volume and improve respiratory function for patients whose posterior convex apex is located in the thoracic spine; (5) This technique can be more convenient to solve the deformity correction via the posterior approach The spinal deformity correction, posterior fixation, and reconstruction of the anterior spinal column can be solved at one time by implanting artificial vertebrae or titanium mesh between the broken ends of the osteotomy via the posterior approach, while inter-screw pressure is applied to make it firmly fixed, and sufficient fragmentation bone grafting can be performed to ensure a high fusion rate. Due to the reliable fixation, the patient can go down to the floor early. At present, the posterior convexity correction rate of this procedure reaches 70%, and patients can resume activities on the ground sooner after surgery. The follow-up results show that the bone graft is well fused, with little correction loss, safe and reliable, and good long-term results.