Table 7.
Interater reproducibility for the radiographic parameters
| Parameters | Unit | ICC (95%CI) | SEM | SEM (%) | MDC |
|---|---|---|---|---|---|
| Pelvic rotation (CSL to symphysis) | mm | 0.59 (0.34 to 0.76) | 1.3 (1.0 to 1.6) | 70.9 (55.0 to 99.5) | 2.5 |
| Pelvic flexion (SC joint to symphysis) | mm | 0.70 (0.48 to 0.83) | 7.0 (5.7 to 9.1) | 23.5 (18.8 to 31.4) | 13.8 |
| Femoral head diameter | mm | 0.90 (0.81 to 0.95) | 1.8 (1.5 to 2.3) | 2.9 (2.4 to 3.8) | 3.5 |
| Length of acetabulum | mm | 0.81 (0.66 to 0.90) | 3.2 (2.6 to 4.1) | 5.8 (4.7 to 17.4) | 6.2 |
| Fossa to ilioischial line | mm | 0.58 (0.32 to 0.76) | 2.4 (2.0 to 3.1) | 44.1 (30.0 to 86.0) | 6.8 |
| Neck-shaft angle | Degrees | 0.58 (0.31 to 0.76) | 4.4 (3.6 to 5.7) | 12.2 | |
| Tonnis angle | Degrees | 0.45 (0.15 to 0.67) | 3.4 (2.8 to 4.4) | 9.3 | |
| Sharp’s angle | Degrees | 0.63 (0.40 to 0.79) | 1.8 (1.5 to 2.4) | 5.0 | |
| Lateral CEA | Degrees | 0.73 (0.53 to 085) | 3.0 (2.5 to 3.9) | 8.3 | |
| Alpha angle (lateral) | Degrees | 0.83 (0.70 to 0.91) | 6.0 (4.9 to 7.7) | 16.6 | |
| Extrusion index | – | 0.90 (0.81 to 0.95) | 1.8 (1.5 to 2.3) | 5.0 |
CSL = center sacral line; SC = sacrococcygeal, CEA = center edge angle; ICC = intraclass correlation coefficient; SEM = standard error of measurement; MDC = minimal detectable change.