Time Matters: Why You Shouldn't Wait to Treat Your Cartilage Injury Skip to content

Time Matters: Why You Shouldn't Wait to Treat Your Cartilage Injury

Image of a knee cartilage lesion as it gets larger over time

A study shows us why patients shouldn’t wait when it comes to treating their knee cartilage pain.

It can lead to worsening knee cartilage damage and new defects.

The Study Findings

The study “Time Matters” analyzes how delays between cell-based cartilage biopsy and implantation can allow a patient’s cartilage damage to grow larger and new damage to appear.

Researchers examined more than 100 knee ACI (Autologous Chondrocyte Implantation) and MACI cases by a single surgeon. Once candidacy for cell-based therapy is confirmed during a diagnostic arthroscopy, a doctor takes a small cartilage sample for MACI. At a follow up appointment, the doctor will implant MACI to repair a patient’s knee cartilage. The average time between cartilage sample collection and implantation in the study was 155 days (about 5 months).

During that time, patients saw their cartilage damage worsen. The size of patients’ knee cartilage defects increased an average of 0.6 cm2, and 16.2 percent of patients experienced new cartilage defects.

An example of a knee cartilage lesion growing in size. Text explains that the “Time Matters” study found that cartilage defect expansions grew an average of 0.6cm2 between biopsy and implantation. New high-grade defects formed in 16.2 percent of patients.

Who’s at Greatest Risk?

The study found that patients who were male, had smaller initial defect sizes, and longer time between surgeries were at greater risk for defect expansion.

Man experiencing knee cartilage pain

How can I avoid delays in my treatment?

Timely treatment with MACI knee cartilage repair can help heal knee cartilage damage and prevent further deterioration. It is important to spot the symptoms of knee cartilage damage early, and talk to your doctor about your treatment options, timeline and goals.

For more on how MACI knee cartilage repair could help you, click here to explore the procedure.

Please see below for full indication and ISI. Blog posts are intended to provide educational information. Always talk to your doctor with any questions.

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Answer some quick questions to determine your level of pain and to help decide if MACI may be your next best step

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.


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® (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.