Cartilage Defects in the Knee: What Regenerative Medicine Can and Can't Do
Medically reviewed by Dr. Charles Pereyra, MD — Medical Director, Springs Rejuvenation. Last reviewed June 22, 2026.
Written by the Springs Rejuvenation regenerative medicine team from direct clinical experience administering stem cell and exosome protocols at our Aventura, Miami center.
A focal cartilage defect is a small, localized area where the smooth cartilage on the end of a bone has been damaged — often from an injury rather than broad arthritis. Because the damage is contained, these defects are one of the more interesting targets for regenerative medicine. They are also a place where it is easy to over-promise, so this article tries to draw a clear line between what the science supports and what it does not.
Why cartilage barely supports itself
Articular cartilage has no blood supply and very few cells capable of repair. Left alone, a defect tends to stay a defect, and over time the exposed area can place extra stress on the surrounding cartilage. That poor self-repair is the whole reason cartilage has been a major focus of regenerative research.
What regenerative options are being used
Approaches range from cell-based injections to biologic scaffolds used during surgery. The goal of these therapies is to support the formation of new repair tissue within the defect. It is worth being precise here: much of the repair tissue that forms is fibrocartilage, which is more of a durable patch than a perfect replica of the original smooth surface. That can still translate to less pain and better function, which is what most patients actually care about.
What the evidence supports
For well-selected, contained defects in younger and middle-aged patients, regenerative and biologic-assisted approaches have shown the ability to fill defects and improve symptoms in studies. What the evidence does not support is the idea that an injection can rebuild a flawless cartilage surface or reverse widespread arthritis. Honest expectations are the difference between satisfaction and disappointment.
Is a cartilage defect the same as arthritis?
Not exactly. A focal defect is a localized injury, while osteoarthritis is broader, progressive wear. A defect that is left unaddressed can contribute to arthritis over time, which is part of why it draws attention.
Who tends to do best?
Younger and middle-aged patients with a single, contained defect, good alignment, and a stable knee generally have the most favorable odds. Large, diffuse damage is a weaker candidate.
Will I be back to sport?
Many patients return to activity, but cartilage recovery is slow and the timeline is measured in months. Results vary, and your plan will set realistic milestones.
How we evaluate it at Springs
We use imaging to understand the size, depth, and location of the defect, then talk honestly about whether a regenerative plan, a surgical referral, or a combination gives you the best shot. A free consultation is the right first step to get specific answers about your knee.
Medical Disclaimer: Stem cell and exosome therapy is not an FDA approved therapy and is considered to be in the experimental stages. These statements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Springs Rejuvenation processes exosomes in an FDA approved lab. Individual results may vary. This content is reviewed for medical accuracy by Dr. Charles Pereyra, MD, Medical Director of Springs Rejuvenation, and is provided for educational purposes only. Always consult a qualified physician.