Fig. 3

A: Subsidence measurements were performed from the anterior, middle, and posterior portions of the vertebral bodies of interest. Subsidence was described as a greater than 3 mm decrease in height of the operative segment between images produced immediately after the operation and those acquired at 2 years follow up. B: The SCA was defined as the angle between the C7 line and the line joining the center of the sellar turcica and the center of the inferior endplate of the C7 body. The center of the St-SVA was defined as the distance between a plumb line from the center of the sellar turcica and the center of the C7 body. C: The C2–C7 SVA was decided as the length from the posterosuperior corner of C7 and the vertical line from the center of the C2 body. The T1 slope was defined as the angle between the upper endplate of T1 and the horizontal line. D: O-s is the angle between the McGregor line and the horizontal line