Fig. 4

Cartilage regions and the meniscus coverage ratio (MCR). a Three regions of femoral cartilage. The green area is the femoral cartilage. The ROI of the femoral cartilage was defined based on bone morphology and surrounded by the blue outer line. The ROI was divided into 27 subregions, indicated by blue lines, and curves were automatically determined by CNN. b Two subregions of the tibial cartilage. c Schematic diagram of the MMCR. For the medial tibial articular surface, the cartilage area, ROI area, and the medial meniscus area and their overlap area are shown in different colors. The red area shows the overlap between the ROI area and the medial meniscus area. The yellow area shows the ROI area that does not overlap with other areas. The green area shows the cartilage area that does not overlap with the other areas. The blue area shows the medial meniscus area that does not overlap with the ROI area. A similar explanation can be given for the lateral meniscus