Table 2.

Distribution of Cervical Pedicle Screws and Pedicle Breaches.

Cervical Level	Total No. of Pedicle Screws		Total No. of Pedicle Breaches		95% Confidence Interval	Pedicle Breaches
						Grade 0		Grade 1		Grade 2		Grade 3		Medial		Lateral
	n	%	n	%		n	%	n	%	n	%	n	%	n	%	n	%
C2	42	14.1	7	16.7	0.070-0.314	35	83.3	6	14.3	0	0.0	1	2.4	1	14.3	6	85.7
C3	28	9.4	6	21.4	0.083-0.410	22	78.6	6	21.4	0	0.0	0	0.0	2	33.3	4	66.7
C4	30	10.1	5	16.7	0.056-0.347	25	83.3	4	13.3	1	3.3	0	0.0	0	0.0	5	100.0
C5	48	16.2	16	33.3	0.204-0.484	32	66.7	9	18.8	5	10.4	2	4.2	2	12.5	14	87.5
C6	52	17.5	17	32.7	0.203-0.471	35	67.3	12	23.1	4	7.7	1	1.9	1	5.9	16	94.1
C7	97	32.7	17	17.5	0.106-0.266	80	82.5	14	14.4	3	3.1	0	0.0	3	17.6	14	82.4
Total	297	100.0	68	22.9	0.182-0.281	229	77.1	51	17.2	13	4.4	4	1.3	9	13.2	59	86.8