Cartilage Cell Implantation (MACI)
A regenerative procedure using your own cartilage cells to repair knee joint damage
Matrix-Induced Autologous Chondrocyte Implantation (MACI) is an advanced cartilage repair technique designed to regenerate new, healthy cartilage in the knee. If you have a larger or more complex cartilage defect, MACI could offer a long-term solution to relieve pain and improve knee function. This procedure is particularly suited for patients whose cartilage damage is too extensive for simpler techniques, such as microfracture. MACI uses your own cartilage cells, which are harvested, cultured, and re-implanted into the damaged area, helping restore the joint and potentially delaying the progression of conditions like osteoarthritis.
HOW IS MACI PERFORMED?
MACI is a two-step procedure that involves harvesting your own cartilage cells and then re-implanting them to repair the damaged area of the knee. Here’s an overview of how the process works:
- Stage 1 | Cartilage Cell Harvesting: In the first stage, Dr Liddell performs a minor arthroscopic procedure to collect a small sample of healthy cartilage from a non-weight-bearing area of your knee. This sample is sent to a specialised lab, where the cartilage cells (chondrocytes) are cultured and expanded over a few weeks.
- Matrix Preparation: Once the cells have been grown in the lab, they are embedded into a biocompatible scaffold, or matrix, which serves as a support structure for the new cartilage to develop.
- Stage 2 | Implantation Surgery: The second stage involves implanting the cell-laden matrix into the damaged area of your knee. This is typically done through a small incision (arthrotomy) to ensure the matrix is securely placed in the cartilage defect. Over time, the matrix allows the new cartilage to grow and integrate with the surrounding tissue.
POTENTIAL BENEFITS OF MACI
MACI offers several key benefits, especially for patients with larger cartilage defects. Here’s why it might be a good option for you:
- Regenerates Hyaline-Like Cartilage: Unlike other procedures that generate less durable fibrocartilage, MACI promotes the growth of hyaline-like cartilage. This type of cartilage is more similar to your original cartilage, making it more resilient and better suited to withstand the demands of daily activities.
- Customised Repair: Because MACI uses your own cartilage cells, the newly formed cartilage is highly compatible with your knee, reducing the risk of complications or rejection.
- Effective for Larger Defects: MACI is particularly beneficial for larger cartilage defects, usually greater than 2 cm², where simpler techniques may not be sufficient to restore knee function.
- Delays or Prevents Osteoarthritis: By repairing cartilage with durable tissue, MACI can relieve pain, improve knee mobility, and potentially delay or prevent the onset of osteoarthritis.
LIMITATIONS OF MACI
While MACI offers long-term benefits, there are some factors to consider when deciding if it’s the right option for you:
- Two-Stage Procedure: MACI requires two separate surgeries—one to harvest the cartilage and another for the implantation—making it a more involved process compared to other treatments.
- Longer Recovery Time: Because MACI involves regenerating new cartilage, recovery can take longer. Patients need to follow a strict rehabilitation plan to ensure the best results.
- Cost and Availability: MACI is a specialised procedure and may not be as widely available as other treatments. Additionally, the cost of the procedure is higher due to the complexity of cell culture and matrix preparation.
Recovery and Rehabilitation After MACI
Recovery from MACI is a gradual process that requires a structured rehabilitation plan. Here’s what you can expect during recovery:
- Initial Recovery (First Few Weeks): After the surgery, you will need to avoid putting weight on the affected knee for several weeks. Crutches are commonly used during this time to protect the new cartilage.
- Physiotherapy: A customised physiotherapy program is crucial for your recovery. Early rehabilitation focuses on restoring gentle range of motion, while later stages will involve strengthening exercises to support the knee.
- Gradual Return to Activity: Over time, you can gradually increase your activity level, with an emphasis on low-impact exercises such as swimming or cycling. High-impact activities should be avoided until the knee is fully healed, which may take several months.
IS MACI RIGHT FOR YOU?
MACI may be a good option if you have significant cartilage defects and are looking for a long-term solution to manage knee pain and improve joint function. It is particularly suited for younger, active patients who wish to maintain a high level of physical activity and potentially delay or avoid the need for knee replacement surgery.
Dr Liddell will assess your knee condition, including the size and location of the cartilage defect, and determine if MACI is the most appropriate treatment for your needs.