The amount of blood vessels in the fibrocartilage throughout the meniscus varies. Only the very outer aspect of the meniscus is vascular, which means there is an abundance of blood vessels to allow minor blood flow to the area. The central part of each meniscus has fewer blood vessels and the inner 1/3 does not contain any. As a result, a tear on the very outer peripheral of the meniscus can heal faster than one on the inner portion. Tears in the innermost part of the meniscus will not heal completely due to the lack of blood supply.
Without proper nutrition (blood supply) the menisci may partially disintegrate resulting in less cushioning and protection within the joint. Proper blood flow ensures nutrients and oxygen reach the area and metabolic waste is removed from the fibrocartilage.
When functioning properly, the knee joint naturally receives blood flow through movement and the pumping action of body weight shifting from knee to knee.