Table 3.

Locations of the right and left common iliac veins based on vertical insertion screw trajectory.

	Trajectory toward tip of promontorium (°)		Trajectory parallel to S1 endplate (°)
	Mean ± SD	ICC (95% CL)	Mean ± SD	ICC (95% CL)
A1(R)°	6.00 ± 6.58	0.74 (0.58–0.84)	9.00 ± 8.38	0.74 (0.58–0.84)
A2(R)°	22.00 ± 7.01	0.79 (0.66–0.88)	3.00 ± 8.51	0.79 (0.66–0.88)
A1(L)°	2.00 ± 9.73	0.78 (0.64–0.87)	3.00 ± 8.51	0.78 (0.64–0.87)
A2(L)°	20.00 ± 11.85	0.92 (0.87–0.95)	19.00 ± 9.28	0.92 (0.87–0.95)

A1R°: angle between vertical line (passing from insertion point toward anterior wall of S1) and medial border of the right common iliac vein; A2R°: angle between vertical line and lateral border of the right common iliac vein; A1L° and A2L°: same definitions but on the left side; SD: standard deviation.