Meniscal Allograft Transplantation involves implanting a donor graft (allograft) supplied from a tissue bank in the UK or from the USA. The remnants of the old meniscus are trimmed back to make a fresh bed for the new meniscus which is then inserted by keyhole surgery (arthroscopy) and stitched to the original bed. It then heals to the bed on the side capsule of the knee joint so that it can provide cushioning for the smooth articulating surfaces.
Grafts are donated rather like heart transplant donors and are very carefully prepared by the regulated tissue banks to ensure that the tissue is as free of disease risk as is possible. This process has been highly regulated and advances in testing for infections such as Hepatitis and HIV has meant that the risk of contracting severe infections through the grafting operation are now extremely small. Though difficult to fully quantify, the risk is less than that from a blood transfusion – something that is of course frequently carried out. Grafts are decontaminated and then cryopreserved (very cold) until required.
Unfortunately the strict requirements to have such ideal grafts combined with the need to have the meniscus exactly matched for size based on x-ray measurements, has meant that there is often a delay in obtaining an appropriate graft. Matching can sometimes take many months.