Fig 1.

(1.1 + 1.2) T2-weighted with fat saturation sagittal MRI slices of a patient’s left knee explaining the method of measuring LPTS and MBA. The longitudinal tibial axis was previously calculated in the central sagittal image and then that line was copied to the sagittal slice where lateral tibial plateau was best noticed. A perpendicular line to the longitudinal tibial axis is defined. After, the tangent to the subchondral bone of lateral tibial plateau is drawn, as well as a tangent line to the superior surface of lateral meniscus. LPTS is calculated as the angle between the perpendicular line to the longitudinal tibial axis and the tangent to the subchondral bone of the lateral tibial plateau. MBA is calculated as the angle between the tangent line to the subchondral bone of the lateral tibial plateau and the superior surface of the lateral meniscus. (LPTS, lateral posterior tibial slope; MBS, meniscal bone angle; MRI, magnetic resonance imaging.)