Patients who have a large enough defect in their knee cartilage will sometimes undergo surgery to transplant donor cartilage tissue into their defect in an attempt to repair the knee. The donor cartilage tissue must be fully tested for disease and contamination before it can be placed into a patient. This time, along with the time needed to coordinate the surgery and transport the tissue to the hospital, can be substantial. Cartilage tissue does not last for long outside a body and the fresher the tissue is, the more likely it is that the patient receiving the transplant will heal better.