Table 4.
Subgroup analysis of patients by dichotomization with the 21.7 s cutoff of sit-to-stand test
| Good STS performance (< 21.7 s) |
Poor STS performance (> 21.7 s) |
p-value | |
|---|---|---|---|
| No. (%) | 95 (60.5%) | 62 (39.5%) | |
| PJK incidence (n, %) | 17 (17.9%) | 24 (38.7%) | 0.004 |
| Age | 70.2 ± 8.0 | 73.6 ± 5.4 | 0.004 |
| Sex, female (%) | 80 (84.2%) | 58 (93.5%) | 0.079 |
| BMI | 26.2 ± 3.7 | 26.8 ± 4.2 | 0.312 |
| HGS (kg) | 17.6 ± 8.2 | 18.2 ± 22.1 | 0.804 |
| BMD (g/cm2) | 0.643 ± 0.1 | 0.619 ± 0.1 | 0.176 |
| ODI | |||
| Preop | 42 (31–52) | 46 (34–54) | 0.444 |
| Postop | 33 (22–50) | 38 (20–56) | 0.418 |
| EQ-5D | |||
| Preop |
0.211 (0.081–0.482) |
0.196 (0.081–0.553) |
0.716 |
| Postop |
0.410 (0.143–0.553) |
0.410 (0.103–0.553) |
0.247 |
| PI–LL | |||
| Preop | 46.3 ± 23.5 | 47.0 ± 23.3 | 0.846 |
| Postop | 15.7 ± 10.8 | 14.8 ± 11.4 | 0.600 |
| SVA | |||
| Preop | 172.2 ± 83.9 | 180.8 ± 79.1 | 0.525 |
| Postop | 59.8 ± 40.6 | 63.4 ± 45.0 | 0.619 |
| PJA | |||
| Preop | 1.95 ± 6.03 | 3.37 ± 5.04 | 0.126 |
| Postop | 10.11 ± 8.70 | 13.93 ± 10.46 | 0.016 |
| Fusion length | 8.0 ± 0.7 | 8.0 ± 0.3 | 0.729 |
| Iliac screw insertion | 70 (86.4%) | 41 (95.3%) | 0.216 |
| 3-column osteotomy | 25 (30.9%) | 12 (27.9%) | 0.732 |
STS, sit-to-stand test; PJK, proximal junctional kyphosis; BMI, body mass index; HGS, hand grip strength; BMD, bone mineral density; ODI, Oswestry disability index; EQ-5D, EuroQOL 5- dimension; PI–LL, pelvic incidence and lumbar lordosis mismatch; SVA, sagittal vertical axis; PJA, proximal junctional sagittal Cobb angle
p-value < 0.05 are shown in bold