Preoperative assessment of femoral rotation and its relationship with coronal alignment: A magnetic resonance imaging study

This MRI study explores the individual variation of the rotational axes of the distal femur, and investigate the relationship of this variation with overall coronal alignment in the osteoarthritic knee,The mean surgical epicondylar axis (SEA) was 1.7°, anatomical epicondylar axis (AEA) 5.6° and AP trochlea axis (APA) 94.3° external rotation, compared to the posterior condylar line. Investigating this relationship between different coronal alignment groups, there were statistically significant differences between excessive varus and excessive valgus knees for SEA (0.9:3.0 p < 0.001) and AEA (4.7:7.0 p < 0.001). There was no statistical difference for APA (93.9:95.3 p = 0.238).