Table 2 The AMA table; a certain antetorsion and an intended derotation will give a specific additional change on AMA at a specific measured AMA, reprinted from Imhoff et al. [22]
Antetorsion (°) | 25 | 30 | 30 | 35 | 35 | 40 | 40 | 40 | 45 | 45 | 45 |
|---|---|---|---|---|---|---|---|---|---|---|---|
Derotation (°) | 10 | 10 | 15 | 15 | 20 | 20 | 25 | 30 | 20 | 25 | 30 |
AMA (°) | |||||||||||
3 | 0.2 | 0.3 | 0.3 | 0.4 | 0.5 | 0.7 | 0.8 | 0.9 | 0.8 | 1.0 | 1.1 |
3.5 | 0.4 | 0.5 | 0.6 | 0.8 | 0.9 | 1.0 | 1.0 | 1.1 | 1.3 | ||
4 | 0.3 | 0.3 | 0.5 | 0.6 | 0.7 | 0.9 | 1.0 | 1.1 | 1.1 | 1.3 | 1.5 |
4.5 | 0.5 | 0.7 | 0.8 | 1.0 | 1.2 | 1.3 | 1.3 | 1.5 | 1.6 | ||
5 | 0.3 | 0.4 | 0.6 | 0.7 | 0.9 | 1.1 | 1.3 | 1.4 | 1.4 | 1.6 | 1.8 |
5.5 | 0.6 | 0.8 | 1.0 | 1.2 | 1.4 | 1.6 | 1.5 | 1.8 | 2.0 | ||
6 | 0.4 | 0.5 | 0.7 | 0.9 | 1.1 | 1.3 | 1.5 | 1.7 | 1.7 | 2.0 | 2.2 |
6.5 | 0.7 | 0.9 | 1.2 | 1.5 | 1.7 | 1.8 | 1.8 | 2.1 | 2.3 | ||
7 | 0.5 | 0.6 | 0.8 | 1.0 | 1.2 | 1.6 | 1.8 | 2.0 | 1.9 | 2.3 | 2.5 |
7.5 | 0.9 | 1.1 | 1.3 | 1.7 | 1.9 | 2.1 | 2.1 | 2.4 | 2.7 | ||
The AMA table | Change of AMA (°) = varus increase | ||||||||||