Patient subgroups based on cervical SVA and T1S.
| Variables | All Patients (n = 214) | SVA <4 cm, T1 <20° (n = 28) | SVA ≥4 cm T1 ≥20° (n = 47) | SVA <4 cm T1 ≥20° (n = 139) | P |
| Age, y, mean ± SD (min-max) | 63.5 ± 11.9 (20–86) | 58.5 ± 14.9 (20–79) | 64.8 ± 10.8 (40–84) | 64.1 ± 11.5 (30–86) | >0.05 |
| Gender | |||||
| Men | 134 | 12 | 38 | 84 | >0.05 |
| Women | 80 | 16 | 9 | 55 | |
| Follow-up, y, mean ± SD (min-max) | 1.6 ± 1.3 (0.3–10.8) | 1.76 ± 1.5 (0.3–6.7) | 1.7 ± 1.2 (0.4–5.4) | 1.6 ± 1.3 (0.3–0.8) | >0.05 |
| SVA | |||||
| Preoperative | 31.4 ± 13.9 | 20.2 ± 9.4 | 51.1 ± 9.0 | 27.0 ± 8.6 | <0.01 |
| 6-wk PO | 39.4 ± 16.0 | 27.4 ± 11.0 | 57.1 ± 17.3 | 36.4 ± 11.4 | <0.01 |
| Last PO | 37.6 ± 15.5 | 26.1 ± 10.9 | 55.1 ± 16.4 | 34.0 ± 12.8 | <0.01 |
| P | <0.01 | 0.01 | 0.26 | <0.01 | |
| C2-C7 lordosis | |||||
| Preoperative | 16.4 ± 11.5 | 7.9 ± 5.2 | 16.2 ± 11.1 | 18.2 ± 11.9 | <0.01 |
| 6-wk PO | 12.1 ± 9.6 | 11.6 ± 11.3 | 13.8 ± 9.6 | 11.7 ± 9.2 | >0.05 |
| Last PO | 14.5 ± 10.7 | 10.4 ± 7.9 | 14.4 ± 10.0 | 15.3 ± 11.3 | >0.05 |
| P | <0.01 | 0.12 | 0.12 | <0.01 | |
| T1S | |||||
| Preoperative | 31.2 ± 11.3 | 14.4 ± 5.3 | 39.4 ± 9.6 | 31.8 ± 9.0 | <0.01 |
| 6-wk PO | 28.1 ± 11.7 | 16.5 ± 7.9 | 34.7 ± 10.4 | 28.7 ± 10.8 | <0.01 |
| Last PO | 30.3 ± 10.8 | 17.5 ± 7.1 | 37.1 ± 10.0 | 30.6 ± 9.3 | <0.01 |
| P | 0.19 | 0.23 | 0.11 | 0.08 | |
| T1-(C2-C7 lordosis) | |||||
| Preoperative | 14.8 ± 10.3 | 6.5 ± 7.7 | 22.2 ± 8.1 | 13.7 ± 9.6 | <0.01 |
| 6-wk PO | 16.0 ± 12.5 | 4.7 ± 13.3 | 20.9 ± 11.6 | 17.0 ± 11.0 | <0.01 |
| Last PO | 15.9 ± 12.4 | 7.1 ± 9.1 | 22.7 ± 11.6 | 15.9 ± 12.4 | <0.01 |
| P | 0.57 | 0.11 | 0.75 | 0.14 |
PO, postoperative; SVA, sagittal vertical axis; T1S, T1 slope.