Cartilage Injuries
Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints. Healthy cartilage in our joints makes it easier to move. It allows the bones to glide over each other with very little friction.
Articular cartilage can be damaged by injury or normal wear and tear. Because cartilage does not heal itself well, doctors have developed surgical techniques to stimulate the growth of new cartilage. Restoring articular cartilage can relieve pain and allow better function. Most important, it can delay or prevent the onset of arthritis.
What is Osteochondral Autograft Transplantation (OATS)
In osteochondral autograft transplantation (or OATS surgery), cartilage is transferred from one part of the joint to another.
Normal, non-injured cartilage tissue is taken from a non-weight bearing area of the joint and becomes the "graft," which will be used to replace the injured cartilage area.
The cartilage graft is taken as a cylindrical plug of cartilage with the subchondral (underlying) bone. The plug is then matched to the surface area of the defect and impacted into place. The patient is left with a smooth cartilage surface instead of the previous defect.
Most commonly, just one single plug of cartilage may be taken; however, on occasion, multiple plugs may be necessary to deal with a larger area of injury.
If a cartilage defect is too large for an autograft (your own tissue), an allograft may be considered. An allograft is a tissue graft taken from a cadaver donor. The donor graft is testes, sterilized and prepared in a state of the art laboratory to ensure it is appropriate for transplantation.
The advantage of an allograft is generally its size - it can be used to manage larger areas of injury. The graft can also be shaped to fit the exact contour of the defect and then press fit into place.
MACI (Matrix-induced Autologous Chondrocyte Implantation)
MACI is a two-step procedure in which new cartilage cells are grown and then implanted in the cartilage defect.
This cartilage procedure entails taking some of your own cartilage cells, growing them in a lab and implanting them into your cartilage defect (injury site) embedded on a special collagen membrane. It is a two-step procedure.
The process begins with a minimally invasive biopsy, called an arthroscopy procedure, to procure a sample of your cartilage cells (chondrocytes). This sample is then sent to a laboratory and allowed a period of time to grow.
During a second minimally invasive procedure, your cartilage cell sample will be embedded on a special collagen membrane, then implanted into your knee by your MACI specialist. Learn more about MACI at https://www.maci.com/patients/about-maci/
