High Tibial Osteotomy: Review of Techniques and Biomechanics

Figure 2

Radiographic lower limb alignment assessment. The mechanical axis of the limb (red line) is defined by a line from the center of the femoral head to the medial tibial spine and a line from the medial tibial spine to the center of the ankle. The weight-bearing line (also represented by the red line, as this knee has normal alignment of 0°) is defined by a line from the center of the femoral head to the center of the ankle joint. The anatomic axis of the limb (black line) is defined by mid-diaphyseal lines in the femur and tibia. In a varus knee, the weight-bearing axis passes medial to the medial tibial spine. In a neutral knee, the weight-bearing axis passes through the medial tibial spine. In a valgus knee, the weight-bearing axis passes lateral to the medial tibial spine [32].