Table 1 Basic characteristic of SONFH patients and healthy subjects in this study
Characteristics | Cases (n = 200) | Controls (n = 508) | p |
|---|---|---|---|
Age, years (mean ± SD) | 41.15 ± 12.90 | 42.70 ± 13.01 | 0.152a |
> 40 | 100 (50%) | 290 (57%) | |
≤ 40 | 100 (50%) | 218 (43%) | 0.706b |
Gender | |||
Male | 117 (59%) | 425 (84%) | |
Female | 83 (41%) | 83 (16%) | |
Necrosis | |||
Bilateral | 143 (72%) | ||
Missing | 55 (28%) | ||
Course (months) | |||
> 29 | 61 (31%) | ||
≤ 29 | 139 (69%) | ||