Patient characteristics.
| Characteristics | Instrumented (n = 7) | Uninstrumented (n = 7) | P Value |
| Sex | |||
| Female | 6 (86%) | 6 (86%) | >0.99 |
| Male | 1 (14%) | 1 (14%) | |
| Age, y, mean ± SD (range) | 67.1 ± 5 (56–72) | 64.1 ± 9 (50–74) | 0.47 |
| Follow-up time, y, mean ± SD (range) | 51.7 ± 3.7 (45–57) | 52.2 ± 6.1 (45–59) | 0.89 |