Understanding articular cartilage damage of the knee Skip to content

How your knee works

Your knee is a complex joint serving as the meeting point for three major bones: the tibia (shin bone), the femur (thigh bone), and the patella (kneecap). In order for your knee to flex freely, articular cartilage must protect where hard surfaces come into contact.

Knee x-ray
  • Patella
    Knee cap
  • Tibia
    Shin bone
  • Femur
    Thigh bone
Femur Patella tibia

Healthy cartilage is critical for protecting your knees

Cartilage is a strong, rubbery tissue found in many parts of the body, including joints. There are two types of cartilage found in the knee:

Knee x-ray Meniscus Articular Cartilage
  • Meniscus
  • Articular Cartilage

Healthy cartilage is critical for protecting your knees

Cartilage is a strong, rubbery tissue found in many parts of the body, including joints. There are two types of cartilage found in the knee:

  1. Meniscus—acts as a cushion between the knees
  2. Articular cartilage—covers the ends of the bones to ensure smooth movement
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When cartilage is damaged, it no longer functions well to provide a smooth, impact-resistant coverage of your bone during activities such as walking, kneeling, running, and jumping.

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Cartilage does not heal on its own

Unlike other tissues, cartilage does not naturally regenerate. That’s why cartilage injuries are chronic and frequently get worse as time goes on.

77%

77% of knee pain sufferers say they can no longer participate in at least one activity they previously enjoyed because of knee pain.1

How cartilage can be damaged

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Chronic or repetitive actions

Exercise, sports, or physical work can cause cartilage to weaken and wear over time.

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Acute or traumatic events

Falls and accidents can cause immediate and severe cartilage damage.

See how cartilage damage might affect you as time goes on

Tap or click the spaces along the timeline to see how damage worsens over time

Time

cartilage damage

Symptoms of knee injury2

Pain

Clicking

Swelling

Locking

Physical activities

Walk

Run

Bend down

Play sports

Climb stairs

Work out

Disclaimer: Knee cartilage damage does not heal on its own and may require treatment. Talk to your doctor or an orthopedic specialist to help assess what your next best steps might be.

Are you ready to learn more about your knee pain?

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Not sure what your knee pain is telling you? Take this short quiz to see how much it affects your life.

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Is MACI right for you?
See how the MACI procedure may be your next best step.

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Reference: 1. Data collected from a 2019 Harris Poll survey of 1,002 US adults with knee pain 3 or more days a week that has lasted 2 months or more. 2. Gomoll AH, et al. Surgical management of articular cartilage defects of the knee. J Bone Joint Surg Am. 2010 Oct 20;92(14):2470-90.

Indication and Important Safety Information

Important Safety Information

MACI should not be used if you:

  • are allergic to antibiotics such as gentamicin, or materials that come from cow, pig, or ox;
  • have severe osteoarthritis of the knee, other severe inflammatory conditions, infections or inflammation in the bone joint and other surrounding tissue, or blood clotting conditions;
  • have had knee surgery in the past 6 months, not including surgery for obtaining a cartilage biopsy or a surgical procedure to prepare your knee for a MACI implant;
  • or cannot follow a doctor-prescribed rehabilitation program after your surgery

Consult your doctor if you have cancer in the area of the cartilage biopsy or implant as the safety of MACI is not known in those cases.

Conditions that existed before your surgery, including meniscus tears, joint or ligament instability, or alignment problems should be evaluated and treated before or at the same time as the MACI implant.

MACI is not recommended if you are pregnant.

MACI has not been studied in patients younger than 18 or over 55 years of age.

Common side effects include joint pain, tendonitis, back pain, joint swelling, and joint effusion.

More serious side effects include joint pain, cartilage or meniscus injury, treatment failure, and osteoarthritis.

Please see Full Prescribing Information for more information.

Indication

MACI® is made up of your own (autologous) cells that are expanded and placed onto a film that is implanted into the area of the cartilage damage and absorbed back into your own tissue. MACI is used for the repair of symptomatic cartilage damage of the adult knee.

MACI® (autologous cultured chondrocytes on porcine collagen membrane) is made up of your own (autologous) cells that are expanded and placed onto a film that is implanted into the area of the cartilage damage and absorbed back into your own tissue.

MACI is used for the repair of symptomatic cartilage damage of the adult knee.

The amount of MACI applied depends on the size of the cartilage damage. The MACI film is trimmed by your surgeon to match the size and shape of the damage, to ensure the damaged area is completely covered.

Limitations of Use

It is not known whether MACI is effective in joints other than the knee.

It is not known whether MACI is safe or effective in patients over the age of 55 years.