Regrowing Knee Cartilage: Understanding Matrix Assisted Chondrocyte Implantation

Knee cartilage injuries can cause persistent pain and limit mobility, affecting daily life and physical activity. Unlike many tissues in the body, cartilage has a limited ability to heal on its own. This makes treating a knee cartilage tear challenging. One promising option for cartilage repair is Matrix Assisted Chondrocyte Implantation, or MACI. This advanced technique offers hope for patients looking to restore damaged knee cartilage and regain function.

Illustration of knee cartilage layers and MACI treatment area

Illustration of knee cartilage layers and the area treated by MACI

What Happens When Knee Cartilage Is Injured?

Cartilage is the smooth, rubbery tissue that cushions the ends of bones in joints. It allows bones to glide over each other without friction. When cartilage is damaged by injury or wear, the joint can become painful and stiff. A knee cartilage tear often results from trauma, sports injuries, or degenerative conditions like osteoarthritis.

Because cartilage lacks blood vessels, it receives nutrients through diffusion, which limits its ability to repair itself. Small cartilage injuries may remain stable, but larger tears can worsen, leading to joint pain and reduced mobility.

Traditional Approaches to Cartilage Repair

Conventional treatments for cartilage injury include:

• Physical therapy to strengthen muscles around the knee

• Anti-inflammatory medications to reduce pain and swelling

• Arthroscopic surgery to clean up damaged cartilage

• Microfracture surgery, which stimulates new cartilage growth by creating tiny holes in the bone

  
  

While these methods can provide relief, they often produce fibrocartilage, a type of repair tissue that is less durable than natural cartilage. This can lead to recurring symptoms and further joint damage over time.

What Is Matrix Assisted Chondrocyte Implantation (MACI)?

MACI is a newer, more advanced technique designed to improve cartilage repair outcomes. It involves growing a patient’s own cartilage cells (chondrocytes) in a lab and then implanting them back into the damaged area using a special scaffold or matrix.

How MACI Works

1. Cartilage biopsy: A small sample of healthy cartilage is taken from a non-weight-bearing area of the knee.

2. Cell cultivation: The cartilage cells are isolated and grown in a laboratory for several weeks to increase their numbers.

3. Matrix preparation: The cultured cells are seeded onto a biodegradable scaffold that mimics the natural environment of cartilage.

4. Implantation surgery: The scaffold with the patient’s cells is surgically implanted into the cartilage defect. The matrix helps the cells attach and grow, promoting regeneration of new cartilage tissue.

5. Recovery and rehabilitation: Patients follow a tailored physical therapy program to support healing and restore knee function.

   
   

Benefits of MACI for Knee Cartilage Tears

MACI offers several advantages over traditional cartilage repair techniques:

• Use of patient’s own cells reduces the risk of rejection or complications.

• The matrix scaffold provides a supportive structure for cells to grow in the correct shape and orientation.

• It promotes the formation of hyaline-like cartilage, which closely resembles natural cartilage in durability and function.

• MACI can treat larger cartilage defects that are difficult to repair with other methods.

• Studies show improved pain relief, joint function, and long-term outcomes compared to microfracture surgery.

  
  

Who Is a Candidate for MACI?

MACI is suitable for patients with symptomatic cartilage injuries who have not responded well to conservative treatments. Ideal candidates typically:

• Have a localized knee cartilage tear rather than widespread arthritis

• Are younger and active, aiming to return to sports or daily activities

• Have good overall knee stability and alignment

  
  

Dr. Payne, a specialist in cartilage repair based in Athens, Georgia, evaluates patients thoroughly to determine if MACI is the best option. He considers factors like the size and location of the cartilage injury, patient age, activity level, and overall knee health.

What to Expect During MACI Treatment in Athens, Georgia

Patients in Athens, Georgia, seeking MACI treatment with Dr. Payne can expect a personalized approach:

• Initial consultation and imaging tests to assess the cartilage injury

• Cartilage biopsy procedure performed arthroscopically

• Cell cultivation period lasting about 4 to 6 weeks

• Implantation surgery under anesthesia

• Postoperative rehabilitation guided by physical therapy specialists

  
  

Recovery times vary, but most patients gradually return to normal activities within 6 to 12 months. Following the rehabilitation plan closely is crucial for successful cartilage repair.

Practical Tips for Supporting Cartilage Health

While MACI offers a powerful option for cartilage repair, maintaining knee health is important before and after treatment. Consider these tips:

• Maintain a healthy weight to reduce joint stress

• Use low-impact exercises like swimming or cycling to strengthen muscles without overloading the knee

• Avoid activities that cause sharp knee pain or instability

• Follow your doctor’s advice on supplements or medications that support joint health

• Attend all follow-up appointments to monitor healing progress