Table 1 The definition of the radiographic parameters
Parameter | Definition |
|---|---|
C2–C7 angle | Angle between the lower plate of C2 and the lower plate of C7 |
C0–C2 angle | Angle between the McRae line and the lower plate of C2 |
SVAc2c7 | The horizontal offset from the posterosuperior corner of C7 to the vertebral body of C2 |
TK | Angle between the superior plate of T1 and the lower plate of T12 |
LL | Angle between the superior plate of L1 and the superior plate of S1 |
SVA | The horizontal offset from the posterosuperior corner of S1 to the vertebral body of C7 |
C7PL-CSVL | Vertical distance between the C7 plumb line and center sacral vertical line |
T1 slope | Angle between a horizontal line and the superior endplate of T1 |
TIA | Angle formed by a line perpendicular to the superior endplate of T1 and a line connecting the center of the T1 upper endplate and the upper end of the sternum |
SS | Angle between the horizontal and the sacral plate |
Sacral slanting | The angle between the horizontal line and the upper end plate of the sacrum |
CT | The angle formed between the vertical line from the center of the upper endplate of T1 and the line from the center of the upper endplate of T1 to the center of C2 vertebra |
K-line tilt | The angle between the K-line and a line perpendicular to the horizon |
PI | Angle formed by a line perpendicular to the superior endplate of S1 and a line connecting the center of the S1 upper end plate and the caput femoris |
LPR | The angle formed between a line drawn on the inferior endplate of the last vertebra in the lumbar curve and the iliac crest line |