Microscopic features of the Meniscus



- 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


Evaluation of the neurosensory function of the medial meniscus in humans.

Possible reflex pathway between medial meniscus and semimembranosus muscle: an experimental study in rabbits

A Quantitative Study of the Microstructure and Biochemistry of the Medial Meniscal Horn Attachments

The innervation of the human meniscus.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, May 1, 2012 4:26 pm