Fig. 4

Schematic representation of cartilage thickness measurements. A series of straight line segments perpendicular to both of the polylines were generated. On each line segment, two points were automatically calculated. One point represents the transition between calcified cartilage and cartilage (tidemark), and the other point represents the outer edge of the cartilage. The distance between these points was considered as the cartilage thickness along the line segment. The mean length of all line segments between the two points was calculated as overall cartilage thickness