Table 2 Evaluation of screw position according to vertebral level
At L5 | At S1 | |||||
|---|---|---|---|---|---|---|
Variable | L5-S group | L5-NS group | P | L5-S group | L5-NS group | P |
Screw no. | 68 | 40 | - | 68 | 40 | - |
Grade 0 (%) | 56 (82.4%) | 31 (77.5%) | 0.784 | 45 (66.2%) | 30 (75.0%) | 0.720 |
Grade 1 (%) | 10 (14.7%) | 7 (17.5) | 15 (22.1%) | 7 (17.5%) | ||
Grade 2 (%) | 2 (2.9%) | 2 (5.0%) | 7 (10.3) | 3 (7.5%) | ||
Grade 3 (%) | 0 (0.0%) | 0 (0.0%) | 1 (1.5%) | 0 (0.0%) | ||
Pedicle breach | 12 | 9 | - | 23 | 10 | - |
Lateral (%) | 7 (10.3%) | 6 (15.0%) | 0.468 | 6 (8.8%) | 7 (17.5%) | 0.181 |
Medial (%) | 5 (7.4%) | 3 (7.5%) | 0.978 | 17 (25.0%) | 3 (7.5%) | 0.024 |
Mean SCA (°) | 23.7° ± 7.4° | 23.4° ± 10.6° | 0.945 | 14.7° ± 5.8° | 20.8° ± 5.2° | 0.036 |