Fig. 1

A The measurement of NW, BCW, and condyle width on T2 Coronal view of MRI. A line was drawn through the most inferior boarder of the femoral condyles, and a parallel line was sketched at the level of the popliteal groove. The distance between AB and CD indicated the lateral and medial femoral condyle width, respectively. The distance between AD denoted as the BCW. The distance between BC represented as the NW. B The measurement of the height of medial spine on T2 Coronal view of MRI. The height was defined as the distance from the peak of the tibial spine to the point of the most concave in the tibia. C The intercondylar angle was measured in proton density-weighted axial magnetic resonance images. The angle was shaped by two lines which are from the top of the intercondylar notch to the most inferior border of the intercondylar notch at both medial and lateral condyles