Table 3.
Total inserted, displaced and within-safe margin screws at each level
| Level | Medially displaced screws | Laterally displaced screws | Anteriorly displaced screws | Med + Lat displaced | Total inserted | Accuracy % | Within- safe zone | Safety (%) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| <2 mm | 2.1–4.0 mm | 4.1–6.0 mm | >6 mm | <2 mm | 2.1–4.0 mm | 4.1–6.0 mm | >6 mm | <2 mm | 2.1–4.0 mm | 4.1–6.0 mm | >6 mm | ||||||
| T1 | 1 | 1 | 1 | 2 | 2 | ||||||||||||
| T2 | 1 | 1 | 6 | 7 | 6 | 1 | 15 | 43 | 42 | ||||||||
| T3 | 1 | 1 | 8 | 1 | 1 | 1 | 13 | 47 | 46 | ||||||||
| T4 | 7 | 3 | 6 | 5 | 4 | 21 | 58 | 55 | |||||||||
| A | 10 | 4 | 1 | 20 | 13 | 11 | 2 | 1 | 49 | 150 | 67.3 | 145 | 96.6 | ||||
| T5 | 7 | 7 | 1 | 7 | 5 | 1 | 5 | 28 | 63 | 54 | |||||||
| T6 | 8 | 3 | 5 | 1 | 5 | 1 | 22 | 62 | 54 | ||||||||
| T7 | 3 | 2 | 6 | 4 | 5 | 1 | 20 | 67 | 60 | ||||||||
| T8 | 8 | 1 | 7 | 4 | 3 | 3 | 1 | 23 | 69 | 65 | |||||||
| B | 26 | 13 | 1 | 25 | 14 | 14 | 10 | 1 | 93 | 261 | 64.3 | 233 | 89.2 | ||||
| T9 | 8 | 1 | 1 | 3 | 3 | 2 | 16 | 68 | 64 | ||||||||
| T10 | 8 | 2 | 4 | 4 | 2 | 2 | 1 | 18 | 72 | 68 | |||||||
| T11 | 9 | 1 | 4 | 5 | 1 | 1 | 1 | 20 | 68 | 66 | |||||||
| T12 | 4 | 2 | 1 | 1 | 1 | 8 | 5 | 4 | 3 | 22 | 70 | 61 | |||||
| C | 27 | 6 | 1 | 1 | 10 | 20 | 11 | 9 | 5 | 76 | 278 | 72.6 | 259 | 93.1 | |||
| Thoracic | 63 | 23 | 3 | 1 | 55 | 47 | 25 | 30 | 7 | 2 | 217 | 689 | 68.5 | 637 | 92.4 | ||
| L1 | 1 | 1 | 1 | 8 | 1 | 3 | 2 | 1 | 12 | 67 | 65 | ||||||
| L2 | 2 | 4 | 3 | 2 | 1 | 4 | 1 | 12 | 67 | 64 | |||||||
| L3 | 6 | 2 | 5 | 1 | 3 | 3 | 1 | 17 | 69 | 64 | |||||||
| L4 | 2 | 1 | 2 | 2 | 2 | 4 | 1 | 9 | 70 | 67 | |||||||
| L5 | 1 | 1 | 2 | 2 | 4 | 3 | 6 | 47 | 45 | ||||||||
| Lumbar | 12 | 4 | 2 | 13 | 16 | 7 | 2 | 18 | 5 | 3 | 1 | 56 | 320 | 82.5 | 305 | 95.3 | |
| Total | 75 | 27 | 5 | 1 | 68 | 63 | 32 | 2 | 48 | 12 | 5 | 1 | 273 | 1009 | 72.9 | 942 | 93.3 |
A = T1 + T2 + T3 + T4; B = T5 + T6 + T7 + T8; C = T9 + T10 + T11 + T12