Table 2.

Changes in radiological parameters in two-stage surgery.

Item	Postop-1st − preop	Postop-2nd − postop-1st	P	Correction loss at follow-up
Δ Cobb angle	−7.00 [−9.50, −3.40]	−0.20 [−1.40, 0.70]	0.001*	2.20 [−0.30, 4.30]
Δ L2 wedge angle	−1.80 [−4.50, −0.75]	−0.50 [−1.15, 0.55]	0.029*	0.25 [−0.50, 1.85]
Δ Coronal decompensation	−4.70 [−13.25, −0.15]	−1.40 [−10.15, 0.00]	0.589	1.50 [−0.08, 3.10]
Δ C7 SVA	−11.00 [−36.15, −0.70]	−1.80 [−5.90, 0.00]	0.089	2.10 [−2.10, 13.90]
Δ Lumbar lordosis (LL)	4.90 [3.14, 16.55]	1.10 [−2.40, 2.05]	0.009*	1.90 [−0.70, 3.72]
Δ L4–S1 angle	1.50 [−2.55, 6.00]	0.00 [−3.05, 1.95]	0.309	2.05 [−1.40, 4.90]
Δ L1–L2 angle	4.50 [−0.25, 8.80]	0.30 [−1.70, 0.55]	0.022*	−1.00 [−3.65, 1.30]
Δ PI-LL	−10.28 [−23.55, −3.15]	−0.40 [−2.50, 1.95]	0.004*	0.45 [−2.65, 3.67]

Data are shown as median [interquartile range].

SVA sagittal vertical axis, PI pelvic incidence.

*Significant differences for postop-1st vs. preop and postop-2nd vs. postop-1st.