Table 1.
Two- and three-dimensional acetabular measurements in the supine and standing pelvic positions
| Radiographic measurement | Supine | Standing | p value | ||
|---|---|---|---|---|---|
| Mean ± SD | Range | Mean ± SD | Range | ||
| Sacrococcygeal distance | 35 ± 14 mm | 12–70 mm | 28 ± 18 mm | −10 to 72 mm | < 0.001 |
| LCEA | 31° ± 6° | 20°–49° | 32° ± 6° | 20°–46° | 0.84 |
| Cranial (1:30) acetabular version | 4° ± 10° | −19° to 39° | 6° ± 11° | −23° to 33° | < 0.001 |
| Mid (3:00) acetabular version | 16° ± 7° | 0°–30° | 17° ± 8° | −1° to 37° | < 0.001 |
| Positive crossover sign | 44% | 32% | 0.21 | ||
| Positive posterior wall sign | 46% | 36% | 0.31 | ||
| Positive prominent ischial spine sign | 16% | 20% | 0.60 | ||
| Anterior coverage | 33% ± 4% | 28%–44% | 32% ± 4% | 22%–43% | < 0.0001 |
| Superior coverage | 60% ± 4% | 54%–70% | 59% ± 4% | 53%–69% | 0.0001 |
| Posterior coverage | 46% ± 4% | 37%–57% | 47% ± 5% | 38%–59% | < 0.0001 |
LCEA = lateral center-edge angle.