The meniscus is a tough, fibrocartilaginous ring, which is broad on the outside and very thin on the central aspect. Each knee joint has 2, one on the inner side of your knee (medial), which is “C” shaped and one on the outer side of your knee (lateral), which is more similar to an “O” configuration. They rest between the joint surfaces of the lower aspect of the thigh bone (femur) and the upper aspect of the leg bone (tibia) and function to distribute weight between the two cartilage surfaces. When a substantial portion of the meniscus is torn and is not repairable, wear of the tread surface (articular cartilage) often results. The loss of the articular cartilage is the beginning of degenerative or osteoarthritis of the knee. When a substantial portion of the protective meniscus is missing and you are experiencing pain and swelling unresponsive to conservative treatment, a meniscus transplant may be an option. A whole meniscus is harvested along with its bony attachments from a cadaver (allograft) and carefully tested for sterility. Generally, patients younger than 50 years of age with minimal arthritis are the most appropriate candidates. Normal knee alignment and range-of-motion is a prerequisite. Careful size matching is necessary for an appropriate fit of the transplanted meniscus. During surgery, the remnants of the old meniscus are removed and the joint lining (capsule) is prepared. The tibia is prepared to receive bone plugs or a bone bar, which are normally attached to the harvested meniscus. Following preparation, the allograft meniscus is delivered into the knee and the attached bone is secured into the prepared bony bed. The meniscus rim is sewn to the capsule with multiple sutures. Protected knee motion and limited weight bearing with crutches for 6 – 8 weeks is necessary. Physical therapy assists in regaining knee motion and leg strength. A period of 7 – 9 months may be required for complete healing. The transplanted meniscus can help to protect your knee for a number of years. Low impact activities are recommended. The transplanted meniscus is unlikely to function permanently and 20 – 50% will fail within 10 years of being inserted into the knee.