The US government is helping surgeons by approving the manufacture and use of a new substance that will add to the arsenal of healing options for patients with cartilage damage and defect. After a two year clinical trial and three year follow up of 144 patients, MACi is pipelined for use by orthopedic surgeons. Manufactured in Cambridge, MA, MACi is an acronym for autologous cultured chondrocytes on porcine collagen membranes. This defines a procedure of transplantation of organ tissue or protein from one body part to another from the same person. Doctors will use the mature/healthy cells of a patient's cartilage to repair unhealthy/defective cells. Cartilage, more flexible than bone and tougher than muscle, is nevertheless subject to damage and defect. This may be caused by injury, disease, overuse, and wear and tear. Being able to restore and repair cartilage, especially for patients suffering knee problems, without full knee replacement, using a cellularized scaffold from the patient's own body is a substantial boon. Thousands of knee replacement candidates may have an real alternative to this painful and difficult process!