The knee has two different types of cartilage:  articular cartilage, the substance on the ends of the bones, which allow for a smooth articulation, and the meniscus cartilages, or shock absorbers, that are between the two bones of the knee.  Tears of the menisci are  the most common orthopedic disorder treated by orthopedic surgeons.  A minimally invasive procedure called an arthroscopy entails putting a small fiberoptic camera and small instruments into the knee to repair or remove the torn portions of the meniscus.  For most patients, a complete recovery and return to a functional lifestyle occurs within weeks to a few months.  For some patients, especially those who have lost all of a significant portion of the meniscus, may continue to have pain and swelling in the affected area of the knee.  Just like the shock absorber for your car, if you lose the shock function, the tread on your tire is likely to wear out prematurely.  For patients that have symptoms of meniscus deficiency and a desire to improve pain and function, a cadaveric meniscus transplantation can be done to improve pain and function.  There are criteria that need to be met in order to improve the likelihood of success.  Articular cartilage can also be damaged and can lead to pain and dysfunction.  Articular cartilage has living cells but no blood supply.  As a result, it has no way of regenerating when injured.  For patients with symptomatic articular cartilage defects, an articular cartilage restoration or transplantation can be considered.  The transplants can be cell based, or structural grafts taken for a donor or from another site in the patient’s knee.