Fig. 2.

The schematic diagram of the measurements. F indicates the total width of femoral condyle; M, C, and L indicate the distance from the highest point of the medial condyle, groove, lateral condyle to the posterior condyle line. Trochlear height (medial, central, and lateral) was measured as M/F, C/F, and L/F, respectively. H1 indicates the distance of the top point of boss to the anterior cortex line; H2 indicate the distance between the anterior cortex line and its parallel line through the posterior cortex. Boss height was measured as H1/H2. SA: sulcus angle; MTS: medial trochlear slope; LTS: lateral trochlear slope.