| Angle of knee position [˚] | AM portal relatively standard deviation of radial distortion [%] | AL portal relatively standard deviation of radial distortion [%] | TT portal relatively standard deviation of radial distortion [%] |
| 30 | no visibility | not clear | not clear |
| 50 | 1.56 | not clear | not clear |
| 70 | 1.00 | not clear | 0.21 |
| 90 | 0.62 | 0.57 | 0.36 |
| 110 | 0.35 | 0.48 | 0.24 |
| 130 | 0.63 | 0.80 | 0.62 |