Abstract
The resection of distal femur and proximal tibia during TKR is 90° to mechanical axis but in a normal knee, the joint line is 3°varus. We measured various angles on long-leg alignment radiographs. The mean age was 58.7 years. The mean HKA axis was 4.3°± 0.5°, mPTA was 3.8°±0.5°, mLDFA was 3.6±0.5° and aLDFA was 8.6°±0.5°. The mean HKA & MPTA were approximately 4°varus, mLDFA 4° valgus & aLDFA 8°valgus. The alignment of the knee to its mechanical axis during TKR is therefore not anatomic. This raises a question whether the knee should be aligned to its kinematic axis instead of mechanical axis.
