MACI (Matrix-induced Autologous Chondrocyte Implantation)

Thisis an innovative, new, FDA-approved cartilage restoration procedure that uses your own cells to repair full-thickness cartilage defects in your knee. Using this technique, your knee can regain full function without pain and may even delay or prevent arthritis.


Knee cartilage injuries may be caused by repetitive actions or a traumatic event such as a fall or a direct blow resulting in knee pain, swelling, and restricted range of motion. When compared to muscle or bone, cartilage has a very poor blood supply which makes cartilage injuries very slow to heal with a tendency to get worse with time. When conservative treatments or other options fail to resolve your symptoms, MACI may be your best option to return to what you enjoy.


  • Obtaining the Biopsy: A small biopsy of healthy cartilage is performed from a non-weight bearing portion of the knee.
  • Biopsy Processing: The biopsy is sent to a state-of-the-art processing facility where chondrocytes (the cells which produce cartilage) are extracted from the biopsy and inserted onto a layer of collagen.
  • Chondrocyte Regeneration: The embedded chondrocytes regenerate within the collagen matrix to form implant tissue that can be used to fill the cartilage defect. The process usually takes about 6 weeks.
  • MACI Delivery: The matrix-induced autologous chondrocyte implant is then delivered at the appropriate time to your surgeon for the implant procedure.
  • MACI Implanted: Your surgeon will then shape the collagen matrix to cover your cartilage defect and it is then surgically implanted into your knee.


The benefits of this approach include:

  • No danger of tissue rejection
  • Theoretically, the implanted material will regenerate hyaline cartilage

Who is an ideal candidate?

This procedure is best for young patients with:

  • A single lesion
  • Lesions under 2 cm
  • Healthy subchondral bone


MACI is contraindicated in patients with:

  • Hypersensitivity to aminoglycosides and products of porcine or bovine origin
  • Severe osteoarthritis of the knee
  • Inflammatory joint disease
  • Blood coagulation disorders
  • Knee surgery in the past 6 months

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