- Discussion:
- meniscal cells while typical chondrocytes, are called fibrochondrocytes
because they synthesize fibrocartilage matrix, rather than hyaline
cartilage matrix typical of articular cartilage;
- menisci are composed of circumferentially oriented collagen fibers, which
are parallel to its peripheral border;
- orientation of
type I collagen fiber bundles is the major
determinant of its stiffness (100-300 megapascals) and strength;
- composed of collagen (98% type I), extracellular matrix includes
proteoglycans,
glycoproteins, and elastin;
- chondrocitin sulfate is dominate
glycoaminoglycoside in aggratating
proteoglycan macromolecule;
- interactions of extracellular matrix (water, proteoglycan, & collagen)
account for behavior during compression, tension, & shear;
-
glycoaminoglycoside:
- glycoaminoglycans of adult human consist of condroitin 6 sulfate
(40%), chondroitin 4 sulfate (10-20%), dermatan sulfate
(20-30%), and keratin sulfate (15%);
- Vascular Supply:
- meniscus is vascularized in its prenatal development, however, w/
maturation blood supply extends on to peripheral 1/3;
- Innervation:
- meniscus, unlike articular cartilage, does have within its substance
sensory nerve endings;
- type I and II nerve endings accompany this peripheral vascular supply;
- in adults nerves occupy peripheral 1/3 of the meniscus;
-
central portion:
- midsubstance of meniscus is avascular, aneural,
- fibrochondrocytes are surrounded by an abundant extracellular matrix;
