Table 2.
Comparison of patients with and without screw loosening.
| Characteristic | Screw loosening | p value | |
|---|---|---|---|
| Yes | No | ||
| Number of patients | 42 (20.4%) | 164 (79.6%) | |
| Age (year)∗ | 64.6 ± 11.6 | 60.1 ± 13.1 | 0.03 |
| Sex (F : M) | 0.99 | ||
| Male | 23 | 92 | |
| Female | 19 | 72 | |
| BMI∗ | 24.6 ± 3.2 | 25.6 ± 3.8 | 0.22 |
| DM | 11/42 | 30/164 | 0.47 |
| HTN | 16/42 | 75/164 | 0.47 |
| Smoke | 3/42 | 15/164 | 0.92 |
| Instrumentation | 0.48 | ||
| 1 level | 15/42 | 71/164 | |
| 2 levels | 27/42 | 135/164 | |
| Blood loss (mL)∗ | 822.6 ± 521.6 | 703.6 ± 544.5 | 0.22 |
| Number of screws | 87 (8.2%) | 977 (91.8%) | |
| Screw distribution | |||
| L2 | 0 (0%) | 12 (100%) | |
| L3 | 16 (8.1%) | 182 (91.9%) | |
| L4 | 24 (6.4%) | 352 (93.6%) | |
| L5 | 32 (8.3%) | 354 (91.7%) | |
| S1 | 15 (16.3%) | 77 (83.7%) | |
∗Values are presented by mean ± SD.
BMI = body mass index; DM = diabetes mellitus; and HTN = hypertension.