Autologous chondrocyte implantation (ACI) is a surgical procedure commonly used to treat cartilage defects. However, there are other synonyms that can be used to describe this procedure, such as cell-based articular cartilage reconstruction, chondrocyte transplantation, and autologous cartilage implantation. These terms refer to the same procedure where healthy cartilage cells are harvested from a patient's own body and grown in a laboratory before being implanted back into the affected area. This process helps to regenerate and promote the growth of new cartilage tissue, reducing pain and improving joint function. Other related procedures include matrix-assisted chondrocyte implantation (MACI) and osteochondral autograft transplantation (OATS).