Fig. 2

Measurements of the proximal tibial morphological parameters on magnetic resonance images. The MPTA is measured as the angle between the anatomical axis of the tibia and proximal tibial joint line in the coronal view of the MRI image (a). The central sagittal plane is determined on the slice based on the attachment of the posterior cruciate ligament and intercondylar eminence. In this slice, two circles fitting the anterior and posterior cortices were placed on the tibia. The line connecting the centres of the two circles was used as the tibial axis (b). The MPTS and LPTS are determined by the angle between the axis perpendicular to the tibial axis and the line connecting the two most proximal anterior and posterior subchondral bone points at the centre of the lateral and medial tibiofemoral compartments, respectively (c, d). MPTA medial proximal tibial angle, MRI magnetic resonance imaging, MPTS medial posterior tibial slope, LPTS lateral posterior tibial slope