3D reconstruction of the medial meniscus (green) and lateral meniscus (red); a) meniscal areas are marked (see Figure 1). The total surface area of the meniscus (TOT A) = TA+FA+EA; b) the width and thickness of the meniscus are shown with arrows. The extrusion is measured by the area/distance between the blue intersected line (external edge of the tibial plateau) and the external edge of the meniscus TA. The coverage of the tibial plateau area is determined by the area/distance (i.e. overlap distance) between the blue intersected line and the internal edge of TA.