Fig. 2

a Postoperative standing X-ray of the AS patient after interrupted two-level VCD at T12 and L2. The TK, PT, PI, and SVA were 65.0°, 13.8°, 33.5°, and 131.2 mm, respectively. The total kyphosis of the spine (T4–L3) was 35.9°. The Cobb angle of C2–T1 in the sagittal plane was 50.6°. The Cobb angle of C3–T2 in the coronal plane was 23.4°. b Postoperative photographs of the first stage showing adequate correction of kyphoscoliosis. He cannot see anything within 3 m. His CBVA was − 21.7°