Lenke type 1 primary scoliosis of the thoracic spine. The main thoracic scoliosis is the primary scoliosis, the upper thoracic and thoracolumbar scoliosis is the secondary nonstructural scoliosis Lenke type 2 thoracic bilateral scoliosis. The main thoracic scoliosis is the primary scoliosis, the upper thoracic scoliosis is the structural secondary scoliosis, and the thoracolumbar scoliosis is the nonstructural secondary scoliosis Xie Youzhong, Department of Orthopedics, Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong University Lenke type 3 double primary scoliosis. The main thoracic scoliosis and thoracolumbar/lumbar scoliosis are structural, the upper thoracic scoliosis is nonstructural, and the main thoracic scoliosis is the main scoliosis with a Cobb angle greater than or equal to the thoracolumbar/lumbar scoliosis, or not less than 5° compared to the latter Lenke type 4 triple main scoliosis. Upper thoracic scoliosis, main thoracic scoliosis, and thoracolumbar/lumbar scoliosis are all structural. Both main thoracic scoliosis and thoracolumbar/lumbar scoliosis may be main scoliosis Lenke type 5 thoracolumbar/lumbar scoliosis. The thoracolumbar/lumbar scoliosis is a structural principal scoliosis, the upper thoracic scoliosis and the main thoracic scoliosis are both nonstructural Lenke type 6 thoracolumbar/lumbar scoliosis – main thoracic scoliosis. The thoracolumbar/lumbar scoliosis is the primary scoliosis, which is at least 5° greater than the primary thoracic scoliosis, and the primary thoracic scoliosis is also structural. If the residual angle of the upper thoracic scoliosis on the lateral flexion view is 25° or more, and/or if the deformity of the T2 to T5 level is 20° or more, regardless of whether the first thoracic vertebra is tilted or not, it is determined to be structural. Structural thoracolumbar scoliosis is also characterized by a residual angle of more than 25° and/or a thoracolumbar kyphosis of more than 20°, even though the thoracolumbar kyphosis may be due to a rotational deformity and is not a true kyphotic deformity. This type of scoliosis must be accompanied by thoracic scoliosis of the parietal spine at or above the T11/T12 intervertebral space. If there is any doubt as to whether the CSVL crosses between the bilateral pedicles, then the CSVL is classified as type B. Type B: the CSVL is located between the medial border of the concave pedicle and the outer edge of the vertebral body or disc, and if there is any doubt as to whether the CSVL contacts the vertebral body or outer edge of the disc, then the CSVL is classified as type B. Type C: the CSVL is located outside the outer edge of the lumbar vertebral body or pedicle. If there is doubt as to whether the CSVL is in contact with the vertebral body or the outer edge of the intervertebral disc, it is determined to be type B. Sagittal fractionation of the thoracic spine On a standing lateral radiograph, the sagittal plane of the posterior convexity from the upper edge of the T5 vertebra to the lower edge of the T12 vertebra is measured: a posterior convexity of less than +10° is considered negative (-) a posterior convexity of +10° to +40° is considered normal (N) a posterior convexity greater than +40° is considered positive (+)