11
Planning of Surgery Using the Radiograph
A Anatomical femoral axis
B Anatomical tibial axis
C Mechanical leg axis
D Mechanical femoral axis
E Tibial resection depth (mm)
Valgus
angle
Preop.
Postop.
The following procedure is recommended for
the anterior-posterior whole leg imaging pro-
cess:
1. The femoral axis A (anatomical axis) is drawn
onto the radiograph.
2. A line is drawn from the femoral head to the
center of the knee (mechanical axis D) on the
radiograph.
3. The angle measured between the anatomical
and the mechanical axis = angle
determines
the valgus angle.
4. The tibial axis B is drawn in and the tibial re-
section plane E is determined to avoid exces-
sive resection, especially where there are
defects.
5. The component sizes and resection depths
are determined preoperatively using the
X-ray templates (Lit. No. 1135 or 1584) in A/P
and the lateral planes.
6. The mechanical leg axis C should merge with
lines D and B after correction.
Postop.
Preop.