A maturation change detected in the semilunar cartilages with the scanning electron microscope.

The surface of rabbit, cat, monkey and human semilunar cartilages was examined with the scanning electron microscope. A common feature was the occurrence of numerous ridges, undulations and furrows on the surface, but this was thought to be due to marked shrinkage and distortion of cartilage not firmly attached to bone. Humps were seen on the semilunar cartilages of young animals, but pits occurred in adults. This is thought to reflect a maturation change. Humps were seen in a young human semilunar cartilage, but pits were not seen in adult specimens. It is not clear whether pits are truly absent or just masked by the severe ridging produced during the preparation of large human specimens.