Autologus Chondrocyte Implantation

Candidates for ACI are typically younger adults who have single, isolated areas of cartilage damage in the knee. This surgery is often recommended for patients who have not responded well to other treatments such as physical therapy, medication, or arthroscopic surgery.

ACI is not suitable for people with widespread cartilage damage, as seen in conditions like osteoarthritis. It is also not recommended for those with active infections or certain metabolic diseases.

ACI is a two-stage procedure:

Step one is the cell harvesting. During an initial arthroscopy, your knee surgeon Dr. Mayo removes a small piece of healthy cartilage from a non-weight-bearing area of your knee. This cartilage is sent to a lab, where chondrocytes (cartilage cells) are extracted and cultured to increase their number. This process can take several weeks.

The second stage is called cell Implantation. Once enough chondrocytes have been grown, a second surgery is performed. The surgeon makes an incision over the knee, exposes the area of cartilage damage, and implants the new cells. The new cells then grow over time into new cartilage and fill the defect.

Recovery from ACI can be a long process, often taking 6 to 12 months or longer. During this time, the implanted chondrocytes are growing and maturing into functional cartilage. It may take several weeks before you can bear full weight on the knee, and returning to sports or physically demanding activities will take several months.

After the procedure, you’ll wake up in the recovery room where healthcare providers will monitor you before you go home. You can expect some knee pain, which will be managed with prescribed pain medications. You will be in a knee brace to protect the surgery, and will be able to walk with crutches without putting weight on your leg.

Physical therapy plays a crucial role in the recovery process after ACI. The main goals are to maintain and improve the knee’s range of motion, minimize pain, and gradually strengthen the muscles supporting the knee. The therapist will develop a tailored rehabilitation program, which includes gentle exercises that gradually increase in intensity over time.

Like all surgeries, ACI comes with potential risks, including:

• Infection: A small risk, but if it occurs, it is usually treatable with antibiotics. Antibiotics are given during surgery to minimize this risk.
• Bleeding or Blood Clots: These are infrequent but serious complications.
• Graft Failure: In some cases, the new cartilage may not adhere properly or could be damaged, requiring further treatment.
• Knee Stiffness: Some patients may experience stiffness in the knee joint after surgery.

If ACI is recommended and not pursued, the damaged area of cartilage may continue to worsen. This can lead to increasing pain, instability, and decreasing function of the knee. Over time, this can potentially lead to more widespread cartilage loss and the development of osteoarthritis, which may need a larger surgery.