Table 6.
Intrarater reproducibility for the radiographic parameters measured by Observer 2
| Parameters | Unit | ICC (95%CI) | SEM | SEM (%) | MDC |
|---|---|---|---|---|---|
| Pelvic rotation (CSL to symphysis) | mm | 0.73 (0.54 to 0.85) | 1.2 (1.0 to 1.5) | 94.3 (71.8 to 136.1) | 2.3 |
| Pelvic flexion (SC joint to symphysis) | mm | 0.99 (0.98 to 1.00) | 1.6 (1.3 to 2.0) | 5.8 (4.7 to 7.5) | 3.1 |
| Femoral head diameter | mm | 0.96 (0.92 to 0.98) | 1.2 (1.0 to 1.6) | 2.3 (1.9 to 3.0) | 2.4 |
| Length of acetabulum | mm | 0.96 (0.92 to 0.98) | 1.4 (1.1 to 1.8) | 2.1 (1.7 to 2.7) | 2.7 |
| Fossa to ilioischial line | mm | 0.94 (0.90 to 0.97) | 0.9 (0.8 to 1.2) | 29.7 (22.7 to 42.9) | 2.5 |
| Neck-shaft angle | Degrees | 0.95 (0.90 to 0.97) | 1.8 (1.4 to 2.3) | 4.8 | |
| Tonnis angle | Degrees | 0.88 (0.78 to 0.94) | 2.0 (1.6 to 2.6) | 5.5 | |
| Sharp’s angle | Degrees | 0.55 (0.29 to 0.74) | 1.6 (1.3 to 2.0) | 4.3 | |
| Lateral CEA | Degrees | 0.86 (0.77 to 0.93) | 2.2 (1.8 to 2.8) | 6.0 | |
| Alpha angle (lateral) | Degrees | 0.96 (0.92 to 0.98) | 2.9 (2.4 to 3.7) | 8.0 | |
| Extrusion index | – | 0.80 (0.65 to 0.89) | 1.6 (1.3 to 2.1) | 4.4 |
CSL = center sacral line; SC = sacrococcygeal; CEA = center edge angle; ICC = intraclass correlation coefficient; SEM = standard error of measurement; MDC = minimal detectable change.