Deformity planning for thoracolumbar kyphosis in ankylosing spondylitis: A literature review

Ankylosing spondylitis (AS) is a common inflammatory rheumatic disease that causes characteristic spinal deformities, such as flattening of normal lumbar lordosis and thoracolumbar kyphosis, which may lead to impaired ability of walking, standing, lying on the back and looking straight ahead. Spinal osteotomy is the only effective treatment for this disease. So far, many methods have been designed, and the key is to calculate the exact angle, so as to reconstruct the sagittal balance and the chin-brow vertical angle (CBVA). In this paper, the common methods are reviewed and discussed.