Curious What a Meniscus Is?

I am just curious what a Meniscus is. This is in relation to my post about Radiology Appointment of my husband next month. The reason why he needs an x-ray to his left knee is because of Meniscus. I finally found it now..For more info about it, just visit the URL below

http://en.wikipedia.org/wiki/Meniscus_(anatomy)

In anatomy, a meniscus (from Greek μηνίσκος meniskos, "crescent" is a crescent-shaped fibrocartilaginous structure present in the knee, acromioclavicular, sternoclavicular, and temporomandibular joints[2] that, in contrast to articular disks, only partly divides a joint cavity.[3] A small meniscus also occurs in the radio-carpal joint.

It usually refers to either of two specific parts of cartilage of the knee: The lateral and medial menisci. Both are cartilaginous tissues that provide structural integrity to the knee when it undergoes tension and torsion. The menisci are also known as 'semi-lunar' cartilages - referring to their half-moon "C" shape - a term which has been largely dropped by the medical profession, but which led to the menisci being called knee 'cartilages' by the lay public.