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Table 1 The AMA table; standardized values: Measured antetorsion (top), planned derotation (top), and measured AMA on a frontal plane view (left), equal a defined increase of AMA, which leads to the same increase of mLDFA in an optimal perpendicular cut

From: How to avoid unintended valgus alignment in distal femoral derotational osteotomy for treatment of femoral torsional malalignment - a concept study

Antentorsion (°) 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 0.5 0.6 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