Comparison of patient and surgical factors at the time of revision surgery.
| Variables | No R-PJF (N = 36) | R-PJF (N = 24) | Pa a |
| Patient factors at the revision surgery | |||
| Age, y | 73.6 ± 6.9 | 70.5 ± 6.0 | 0.076 |
| Women | 31 (86.1%) | 20 (83.3%) | 0.768 |
| Femoral neck BMD (T-score) | –1.4 ± 1.3 | –1.5 ± 1.3 | 0.704 |
| Osteoporosis | 7 (19.4%) | 6 (25.0%) | 0.609 |
| Osteoporosis treatmenta | 0.906 | ||
| None | 20 (55.6%) | 15 (62.5%) | |
| Anabolic agents | 11 (30.6%) | 7 (29.1%) | |
| Antiresorptive agents | 5 (13.8%) | 2 (8.4%) | |
| Body mass index | 27.1 ± 3.8 | 26.3 ± 2.8 | 0.392 |
| ASA grade | 2.2 ± 0.4 | 2.3 ± 0.4 | 0.807 |
| Smoking | 5 (13.8%) | 2 (8.3%) | 0.330 |
| Hypertension | 23 (63.9%) | 18 (75.0%) | 0.410 |
| Diabetes mellitus | 13 (54.2%) | 11 (45.8%) | 0.592 |
| Surgical factors at the revision surgery | |||
| Time from index op to revision surgery (mo) | 22.7 ± 17.2 | 32.7 ± 22.3 | 0.226 |
| Failure modes causing revision surgery | 0.166 | ||
| Disc and ligamentous failure | 11 (30.6%) | 5 (20.8%) | |
| Bony failure | 19 (52.8%) | 18 (75.0%) | |
| Implant/bone interface failure | 6 (16.7%) | 1 (4.2%) | |
| Performance of laminectomy | 22 (61.1%) | 9 (37.5%) | 0.687 |
| No. of fusion levels extended | 4.0 ± 2.5 | 4.2 ± 2.7 | 0.840 |
| Final UIV level | 0.743 | ||
| T1–T4 | 5 (13.9%) | 3 (12.5%) | |
| T5–T8 | 12 (33.3%) | 6 (25.0%) | |
| T9–T10 | 19 (52.8%) | 15 (62.5%) | |
| Hounsfield unit of UIV | 172.1 ± 57.1 | 160.5 ± 44.8 | 0.202 |
| Hounsfield unit of UIV + 1 | 186.6 ± 55.2 | 167.0 ± 41.8 | 0.072 |
| Uppermost screw angle (°)b | –0.5 ± 3.2 | 1.0 ± 2.6 | 0.037 |
| Hook fixation at UIV + 1 level | 11 (30.6%) | 5 (20.8%) | 0.404 |
| UIV cement | 12 (33.3%) | 2 (8.3%) | 0.031 |
Abbreviations: ASA, American Society of Anesthesiologists; BMD, bone mineral density; R-PJF, recurrent proximal junctional failure; UIV, uppermost instrumented vertebra.
Note: Data are presented as mean ± SD or n (%). Bold P values indicate statistical significance.
↵a Anabolic agents include teriparatide, and antiresorptive agents include denosumab or bisphosphonate.
↵b Positive value represents the cranial inclination of the pedicle screw relative to the upper endplate.