Table 3.

Correlation between sagittal parameters on lateral X-ray radiographs and the ideal S2AI screw trajectory parameters on CT imaging in deformity patients with AS

Parameters		Left			Right
		GK	PT	SS	GK	PT	SS
Sag angle	r	−0.227a	− 0.618b	0.232a	− 0.220a	− 0.607b	0.284b
Tsv angle	r	0.080	−0.243a	0.052	0.004	−0.239a	0.131
Max-length	r	−0.192	− 0.137	− 0.002	−0.304b	− 0.176	−0.14
Sacral distance	r	−0.023	0.133	−0.084	0.026	0.103	−0.089
Iliac width	r	0.043	0.458b	−0.103	0.062	0.324b	−0.096
S2 midline	r	0.169	0.039	−0.079	0.133	0.445b	−0.098
Skin distance	r	0.148	−0.038	−0.238a	0.113	−0.053	− 0.250a
Iliac wing	r	0.018	0.162	−0.139	−0.007	0.178	−0.052
PSIS distance	r	0.062	−0.135	−0.201	0.063	−0.109	− 0.166

PT Pelvic tilt, GK Global kyphosis, PSIS Posterior superior iliac spine

^aSignificant correlation was established at the 0.05 level

^bSignificant correlation was established at the 0.01 level