Table 2.
Results of the radiological assessment of pedicle screw placement
| Total (%) | T (%) | L (%) | Dx (%) | Sin (%) | Cc (%) | Cx (%) | Apex (%) | None-apex (%) | |
|---|---|---|---|---|---|---|---|---|---|
| Medial placement | 54 (6.1) | 44 (81) | 10 (19) | 14 (26) | 40 (74) | 33 (61) | 21 (39) | 15 (28) | 39 (72) |
| Lateral placement | 70 (8) | 65 (93) | 5 (7) | 38 (54) | 32 (46) | 30 (43) | 40 (57) | 26 (37) | 44 (63) |
| Anterior cortical perforation | 13 (1.5) | 13 (100) | 0 (0) | 3 (23) | 10 (77) | 10 (77) | 3 (23) | 2 (15) | 11 (85) |
| Endplate perforation | 8 (0.9) | 1 (12) | 7 (88) | 6 (75) | 2 (25) | 6 (75) | 2 (25) | 2 (25) | 6 (75) |
| Foraminal perforation | 4 (0.5) | 2 (50) | 2 (50) | 0 (0) | 4 (100) | 4 (100) | 0 (0) | 2 (50) | 2 (50) |
| Misplacement: Total | 149 (17) | 125 (84) | 24 (16) | 61 (41) | 88 (59) | 83 (56) | 66 (44) | 47 (31) | 102 (69) |
| Normal placement | 721 (82.7) | 560 (78) | 161 (22) | 253 (35) | 468 (65) | 444 (62) | 277 (38) | 209 (29) | 512 (71) |
| Questionable | 3 (0.3) | 3 (100) | 0 (0) | 2 (67) | 1 (33) | 1 (33) | 2 (67) | 0 (0) | 3 (100) |
| Total (all screws included in analysis) | 873 (100) | 688 (79) | 185 (21) | 316 (36) | 557 (64) | 528 (61) | 345 (39) | 256 (29) | 617 (71) |
T thoracic, L lumbar, Dx right, Sin left, Cc pedicle screws inserted on the concave side of the curve, Cx pedicle screws inserted on the convex side of the curve, Apex pedicle screws inserted at the scoliotic apex, None-apex pedicle screws inserted at levels other than apex