Autologous Chondrocyte Implantation
Autologous chondrocyte implantation (ACI) is accomplished in two steps. The first step involves growing new cartilage cells followed by the implantation of these new cells into the defect.
The first step is performed arthroscopically during which healthy cartilage cells are removed from a non-weight bearing area of the bone. These cells are then cultured in a laboratory for 3-5 weeks to increase their number.
Implantation of the new cartilage cells is performed through an open surgical procedure called arthrotomy.
Arthrotomy involves preparation of the defect following which a layer of the bone-lining (periosteum) is stitched over the defect and sealed with fibrin glue. The cultured cells are then injected into the defect just below the cover.
Autologous chondrocyte implantation is indicated in younger patients who have a single, larger lesion over 2 cm in diameter. As the patient’s own cells are used, there is no risk of tissue rejection.