Application of CT Scanning in the Studies of Minimal Invasive Thoracoscopic Surgery of Adolescent Idiopathic Scoliosis

Abstract

Adolescent idiopathic scoliosis (AIS) is a structural, lateral, rotated curvature of the spine that arises in otherwise healthy children at or around puberty, for which no cause has be established. (Lowe TG, et al. 2000, Weinstein SL, et al. 2008, Wang WJ, et al. 2011) The diagnosis is one of clinical and radiographic exclusion, and is made only when other causes of scoliosis, such as vertebral malformation, neuromuscular disorder, syndromic disorders, connective tissue disorders and genetic syndromes, have been ruled out. Spinal deformity is usually noted by a school screening examination, a pediatrician, or a family member observant to the changes seen in the trunk including: unlevel shoulders, waistline asymmetry, and thoracic or lumbar prominences. The diagnosis is confirmed on longcassettal coronal and lateral radiograph of the spine, with a Cobb measurement greater than or equal to 10°. In addition, the radiographs should exclude congenital anomalies of the spine and atypical curve patterns, such as left thoracic curves that may be associated with syringomyelia. With this definition, epidemiological studies estimate the prevalence of 1-3% in the at-risk population (children aged 10-16 years). In these patients, the most common type of AIS is main right thoracic curve (RT). The size of the curve tends to increase over the entire lifetime, but the fastest progression happened during pubertal growth. Female showed a significant higher tendency of progression than male AIS patients, with the ratio of 9:1 or 10:1 with curves greater than 40°, at which a surgical intervention would be recommended with the aim of arresting progression, achieving maximum permanent correction of the deformity in three dimensions, improving appearance by balancing the trunk, and keeping short-term and long-term complications to a minimum. Both posterior and anterior instrumentation methods have been used successfully in surgical treatment of AIS. The AIS patients with a primary thoracic curve have the highest prevalence of progression. When the curve pattern is such that only thoracic instrumentation is required, the choice between anterior and posterior surgical approach exists. Segmental posterior spinal instrumentation and fusion has been accepted as the gold standard method in treating RT-AIS, for the consistent correction rate in short and long term, and low incidence of complication. (Weinstein SL, et al. 2008) In contrast, anterior scoliosis surgery was introduced with the ability to create thoracic kyphosis and better correct vertebral rotation and torsion, and with the fusion of