Table 1.
Patient demographics and imaging analyses
| Variable | M group (n = 118) | WM group (n = 45) | p-value |
|---|---|---|---|
| Age (yr) | 66.2 ± 11.3 | 66.5 ± 10.1 | 0.864 |
| Sex | |||
| Male | 81 (68.6) | 27 (60) | 0.297 |
| Female | 37 (31.4) | 18 (40) | |
| BMI (kg/m2) | 25.7 ± 4.6 | 23.9 ± 2.7 | 0.084 |
| JOA score | 12.4 ± 3.0 | 17.0 ± 0.0 | < 0.001* |
| OP-index of the cervical spine | 7.4 ± 2.3 | 7.8 ± 2.7 | 0.310 |
| OPLL type | 0.153 | ||
| Continuous | 22 (18.6) | 4 (8.9) | |
| Segmental | 24 (20.3) | 5 (11.1) | |
| Mixed | 54 (45.8) | 27 (60) | |
| Localized | 18 (15.3) | 9 (20) | |
| Morphological type | 0.533 | ||
| Nonbridge formation | 134 (30.8) | 59 (35.3) | |
| Stable plate | 30 (6.9) | 14 (15) | |
| Stable beak | 30 (6.9) | 6 (3.6) | |
| Unstable upper-plate | 66 (15.2) | 25 (8.4) | |
| Unstable lower-plate | 44 (10.1) | 19 (11.4) | |
| Unstable-beak | 131 (30.1) | 44 (26.3) | |
| Axials type | 0.043* | ||
| Central | 69 (58.5) | 34 (75.6) | |
| Lateral | 49 (41.5) | 11 (24.4) | |
| K-line (+) | 86 (72.9) | 38 (84.4) | 0.152 |
| K-line (-) | 32 (27.1) | 7 (15.6) | |
| Bridge-formation | |||
| C2/3 | 51 (43.2) | 26 (57.8) | 0.096 |
| C3/4 | 69 (58.5) | 25 (55.6) | 0.736 |
| C4/5 | 63 (53.4) | 21 (46.7) | 0.443 |
| C5/6 | 68 (57.6) | 18 (40.0) | 0.044* |
| C6/7 | 58 (49.2) | 13 (28.9) | 0.020* |
Values are presented as mean±standard deviation or number (%).
M group, myelopathy group; WM group, without myelopathy group; BMI, body mass index; JOA, Japanese Orthopaedic Association; OPindex, ossification index; OPLL, ossification of the posterior longitudinal ligament.
*
p < 0.05, statistically significant differences.