Table 3.

Pedicle screw breach distribution by degree of violation and level instrumented

	<2 mm		2–4 mm		>4 mm		Total
	Med	Lat	Med	Lat	Med	Lat
T1	0	0	0	0	1	0	1
T2	0	0	1	1	0	0	2
T3	1	0	0	1	0	0	2
T4a	1	0	1	4	1	0	7
T5	2	0	3	6b	0	1	12
T6	0	0	1	1	0	0	2
T7	1	0	0	2	0	0	3
T8	0	1	0	0	0	1	2
T9	0	0	0	2	0	0	2
T10	0	0	0	2	0	0	2
T11	0	0	0	0	0	1	1
T12	0	1	3	0	0	0	4
Total	5	2	9	19	2	3	41a

^aOne of the T4 screws also had an anterior violation of 1–2 mm

^bOne of the T5 screws also had a lateral violation of 2 mm and an anterior violation of 2–4 mm