What is Autologous Chondrocyte Implantation?

Autologous chondrocyte implantation is a surgical procedure that is performed on a patient to repair damaged cartilage in the knee. Cartilage serves as a cushion between bones but when it is damaged, it cannot repair itself. Chondrocytes are cells that secrete cartilage and these cells can be used as a biomedical treatment to repair cartilage.

If a patient sustains a knee injury or trauma that damages the cartilage, he or she may qualify for autologous chondrocyte implantation. The procedure cannot be performed on patients suffering from osteoarthritis or rheumatoid arthritis since those conditions cause the cartilage to break down and any new cartilage would deteriorate as well. Autologous refers to harvesting and implanting the patient’s own cells.

A patient who experiences pain, swelling, or restricted movement of the knee would first need to have X-rays or a magnetic resonance imaging (MRI) done of the area. The surgeon would then decide whether to perform the autologous chondrocyte implantation. This surgery is done in two steps with the first step being a minimally invasive arthroscopic surgery. A camera is inserted into the knee joint to examine any damage to the cartilage. At the same time, a small biopsy or sample can be taken of the cartilage.

This cartilage sample is sent off to a lab where the cells are extracted from the cartilage with enzymes. These cells are then cultured in a tissue culture dish in the lab where they will grow and divide and generate millions of cells. Cells can grow outside of the body in a protein solution containing nutrients and serum taken from the patient. After several weeks, the laboratory delivers the patient’s cells back to the surgeon and the second part of the surgery is scheduled.

The second step of the surgery is done by making an incision into the knee area to expose the damaged cartilage. A piece of the periosteum, the outer membrane covering the bone, is carefully removed from a bone in the knee area. The periosteum is sewn over the area of damaged cartilage and the surgeon can then inject the cultured cells through the membrane into the cartilage. These cells will then secrete cartilage and should repair the defective area.

For the first 10-12 weeks after surgery, the patient will need to avoid twisting or putting any weight on the knee. The patient should follow the exercise program recommended by the surgeon or physical therapist. Complete recovery from the autologous chondrocyte implantation may take several months to a year.