Table 5.
Intrarater reproducibility for the radiographic parameters measured by Observer 1
| Parameters | Unit | ICC (95%CI) | SEM | SEM (%) | MDC |
|---|---|---|---|---|---|
| Pelvic rotation (CSL to symphysis) | mm | 0.83 (0.69 to 0.91) | 0.8 (0.6 to 1.0) | 25.8 (20.6 to 34.6) | 1.5 |
| Pelvic flexion (SC joint to symphysis) | mm | 0.94 (0.89 to 0.7) | 2.3 (1.9 to 3.0) | 5.8 (4.7 to 7.6) | 4.4 |
| Femoral head diameter | mm | 0.90 (0.81 to 0.95) | 1.6 (1.3 to 2.1) | 2.9 (2.3 to 3.7) | 3.1 |
| Length of acetabulum | mm | 0.97 (0.94 to 0.98) | 1.4 (1.1 to 1.8) | 2.0 (1.6 to 2.6) | 2.7 |
| Fossa to ilioischial line | mm | 0.86 (0.74 to 0.92) | 1.4 (1.2 to 1.8) | 29.4 (20.0 to 54.8) | 3.9 |
| Neck-shaft angle | Degrees | 0.94 (0.89 to 0.97) | 5.7 (4.7 to 7.5) | 15.9 | |
| Tonnis angle | Degrees | 0.95 (0.90 to 0.97) | 0.7 (0.6 to 1.0) | 2.0 | |
| Sharp’s angle | Degrees | 0.84 (0.71 to 0.91) | 1.2 (1.0 to 1.6) | 3.4 | |
| Lateral CEA | Degrees | 0.97 (0.93 to 0.98) | 1.1 (0.9 to 1.4) | 3.0 | |
| Alpha angle (lateral) | Degrees | 0.98 (0.96 to 0.99) | 2.1 (1.7 to 2.7) | 5.8 | |
| Extrusion index | – | 0.96 (0.92 to 0.98) | 1.3 (1.0 to 1.6) | 3.5 |
CSL = center sacral line; SC = sacrococcygeal; CEA = center edge angle; ICC = intraclass correlation coefficient; SEM = standard error of measurement; MDC = minimal detectable change.