- See:
- Metaphyseal Artery
- Nutrient Artery
- Periosteal Artery
- Discussion:
- in femoral and radial heads which are almost entirely covered by cartilage,
- vessels enter in region between articular cartilage & growth-plate cartilage, and hence, the blood supply is tenuous;
- in other regions, the epiphysis has openings that permit passage of large number of vessels into and out of the ossification centers;
- growth plate itself is avascular & receives nutrition from 2 sources;
- epiphyseal vessels that supply resting, germinal, proliferating, and upper hypertrophic cell layers by diffusion
- metaphyseal vessels that supply zone of provisional calcification;
- in young child, epiphyseal vessels are separated from metaphyseal vessels, but following growth arrest of the cartilage plate, there is an extensive anastomoses between epiphyseal vessels, metaphyseal vessels, & terminal branches of Nutrient Artery;
- obliteration of epiphyseal blood supply results in necrosis of epiphysis & deprives deeper cartilage cells of growth plate of their nutrition;
- longitudinal growth ceases, &, if collateral circulation is not quickly restored, permanent closure of epiphyseal plate occurs;
- epiphyseal vessels are responsible for permitting longitudinal growth to occur, whereas metaphyseal vessels nourish osteoprogenitor cells, which lay down bone on cartilage matrix