Figures & data
Figure 1. Screen display showing the inclination and anteversion of the cup, the anteversion and varus/valgus angle of the stem, and the leg length compared with the contralateral side.
Figure 2. Evaluation using postoperative CT. Each angle is displayed on the screen.
Figure 3. Mean deviation of cup anteversion, inclination and stem anteversion using navigation and manual methods. There is only a significant difference for cup anteversion.
Figure 4. Mean deviation of leg length compared with the contralateral side using navigation. 52 of the 56 cases are within 5 mm, and 41 of the cases are within 2 mm.
Figure 5. Mean deviation of cup inclination, cup anteversion and leg length using 3-mm and 1-mm CT slices. The deviation of the two cup parameters showed no significant difference.
Figure 6. Although the varus angle of this stem is accurate to 3°, it appears to be ill-shapen on the X-ray. This demonstrates that accurate numerical values for the varus/valgus angle do not guarantee good results.
