Alignment values measured preoperatively for spinopelvic and lower extremity alignment parameters across increasing patient age groups.
| Actual Postoperative Alignment | Age Group | P | ||
| <40 y | 40–65 y | ≥65 y | ||
| Spinopelvic | ||||
| Sagittal vertical axis (mm) | −14 ± 15.6 | −1.2 ± 48.3 | 16.8 ± 46.8 | 0.050 |
| Pelvic tilt (°) | 7.8 ± 4.8 | 15.7 ± 9.1 | 24.3 ± 9.5 | <0.001 |
| Pelvic Incidence minus lumbar lordosis (°) | −9.2 ± 9.8 | −3.5 ± 11.9 | 5.7 ± 14.2 | 0.002 |
| Lumbar lordosis and thoracic kyphosis (°) | 22.1 ± 14.5 | 15.4 ± 13.4 | −1 ± 22 | <0.001 |
| Lower extremity | ||||
| Sacrofemoral angle (°) | 205.5 ± 12.7 | 199.3 ± 9.4 | 198.3 ± 11.4 | 0.312 |
| Knee angle (°) | 0.06 ± 4.2 | 3.7 ± 6.2 | 1.3 ± 5.7 | 0.743 |
| Ankle angle (°) | 4.5 ± 2.3 | 6.6 ± 3.1 | 5.5 ± 2.9 | 0.858 |
| Pelvic shift (mm) | 20 ± 23.5 | 21.6 ± 30.3 | 15.3 ± 36.5 | 0.617 |
Note: Boldface indicates statistical significance.