Radiographic parameters

Radiographic parameters were determined with an accuracy of 0.1 mm using mediCAD® (Hectec, Landshut, Germany). The following parameters were assessed in accordance to Paley [6]:

Mechanical medial proximal tibial angle (mMPTA)

Mechanical lateral distal femoral angle (mLDFA)

Mechanical lateral proximal femoral angle (mLPFA)

Anatomic Mechanical Angle of the femur (AMA)

Femoral torsion

Hip Knee Ankle (HKA) angle, refers to the angle between mechanic axes of the femur and the tibia (Fig. 3). A synonym for HKA is the mechanical tibiofemoral angle (mTFA).

Illustration of the radiographic parameters measured on a long-leg standing X-ray with the knees pointing forward. Measures around the hip and the knee. HKA: Hip Knee Ankle angle, mLDFA: Mechanical lateral distal femoral angle, mLPFA: Mechanical lateral proximal femoral angle, mMPTA: Mechanical medial proximal tibial angle

At the level of the ankle, we measured the following radiographic parameters (Fig. 4):

Anatomic Lateral Distal Tibia Angle (aLDTA)

Mechanical Lateral Distal Tibia Angle (mLDTA)

Mechanical Malleolar Angle (mMA)

Malleolar Horizontal Orientation Angle (MHA)

Tibia Plafond Horizontal Orientation Angle (TPHA)

Tibio Talar Tilt Angle (TTTA)

Illustration of the radiographic parameters measured on a long-leg standing X-ray with the knees pointing forward. Measures around the ankle. a mLDTA: angle between tibiaplafond and mechanical tibia axis. b mMA: angle between malleolar tips and mechanical tibia axis. c MHA: angle between malleolar tips and floor. d TPHA: angle between tibiaplafond and floor. e TTTA: angle between tibio-talar joint surfaces. mLDTA: Mechanical lateral distal tibia angle, mMA: Mechanical Malleolar Angle, MHA: Malleolar Horizontal Orientation Angle, TPHA: Tibia Plafond Horizontal Orientation Angle, TTTA: Tibio Talar Tilt Angle