Table 1.
Descriptive summary of patient cohort
| Descriptive parameter | Mean (SD) or number (%) |
|---|---|
| Total number of patients | 249 |
| No PJK group | 207 (83.1%) |
| PJK group | 42 (16.9%) |
| Female | 214 (85.9%) |
| Mean age (years) | 35 (19) |
| < 18 years | 91 (36.8%) |
| 19–29 years | 22 (8.1%) |
| 30–39 years | 25 (10.1%) |
| 40–49 years | 42 (17.0%) |
| > 50 years | 69 (27.7%) |
| Osteoporosis or osteopenia | |
| Normal | 156 (62.7%) |
| Osteopenia | 16 (6.4%) |
| Osteoporosis | 77 (30.9%) |
| Fusion to S1 | 57 (22.9%) |
| Thoracoplasty | 75 (30.1%) |
| Surgical approach | |
| Anterior only | 14 (5.6%) |
| Posterior only | 147 (59.0%) |
| Anterior-posterior | 88 (35.3%) |
| Instrumentation technique | |
| Hook/hybrid | 182 (73.1%) |
| Pedicle screw | 40 (16.1%) |
| Vertebral body screws (anterior) | 25 (10.0%) |
| Wires | 2 (0.8%)* |
| Upper instrumented level | |
| T1 to T3 | 83 (33.3%) |
| T4 to T12 | 163 (65.5%) |
| L1 or below | 3 (1.2%)* |
| Levels fused | 10.64 (3.13) |
| PJK angle | 3.36º (7.28º) |
| SSVL difference (mm) | −4.40 (40.45) |
| SRS score difference | 3.73 (0.53) |
| Followup (years) | 3.9 (2.3) |
* Excluded from data analysis due to low numbers; PJK = proximal junction kyphosis; SSVL = sacral sagittal vertical line difference between pre- and postoperative time; SRS = Scoliosis Research Society.