Fig 3.

Radiographic determination for the degree of correction for an opening-wedge distal femoral osteotomy on the left knee to correct for valgus alignment. Long-leg standing radiographs are used for the assessment. To determine the size of correction for valgus alignment, 2 lines should be drawn, one from the center of the femoral head through the center of the knee, and another from the center of the talus to the center of the knee. Next, a line is measured where the osteotomy correction will occur in the femur, ensuring to maintain a 1-cm cortical hinge medially. That same distance should be measured distally from where the 2 vertical lines intersect in the center of the knee, at which point the distance between the 2 verticals is the size of the correction to obtain neutral alignment. For this patient, the plate was determined to require a 5-mm osteotomy plate.