The histological structure of dog knee menisci with comments on its possible significance.

Knee-joint menisci are poorly understood terminologically, structurally and functionally in spite of their almost universal occurrence in mammals and their considerable clinical significance in man. A study was therefore undertaken of dog knee menisci utilizing several histological techniques. Terminologically, it is proposed that the part of the meniscus extending between the anterior and posterior horns and exclusive of them be called the meniscal "body." Structurally, the horns and body differ in anumber of ways. The horns are oval in cross section, the body triangular. Hyalinized areas are much more frequent in the body than in the horns. The collagen of the horns is organized into discrete bundles that are separated from one another by loose connective tissue septa, while that of the body is arranged in a "herringbone" pattern; no septa are present in the body. Finally, the meniscal horns are richly supplied with blood vessels are nerves (including large myelinated fibers which apparently terminate in the horns) while the body is almost completely devoid of blood vessels and nerves. Functionally, it is hypothesized that knee-joint menisci may serve important sensory functions.