Degeneration of the menisci of the knee joint occurs as a typical change of progressive age. The severity of degeneration does not always parallel age. This degeneration is noted equally in both menisci, and in menisci which have been surgically removed, as well as in menisci which have remained intact in the knee. The term "meniscosis" is suggested to describe the degenerative changes which the meniscus undergoes. The exact relation between degeneration of the meniscus and the alteration of the blood vessels described is quantitatively uncertain. The menisci tend to regress under several factors which include daily small traumata of subclinical import, poor vascularity quite independent of vessel pathology, the presence of intra-articular disease, vessel alterations which are so frequently present, and probable alterations in synovial nutrition. Hempel has indicated that cartilage may be destroyed by ferments in the synovial fluid. If this is true, this may hold true too for the menisci, which receive some nutrition from the synovial fluid.

Meniscitis does not exist as an entity. Meniscosis need not express itself clinically; though rarely, in the later decades of life, it may be the cause of pathological fracture of the meniscus, in a patient without a history of trauma or in association with arthritis. Meniscal cysts are degenerative in origin.