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What is Articular Cartilage?



What is Articular Cartilage?

Articular cartilage is the firm, white covering on the ends of the bones. Articular cartilage injury treatment is called for when the cartilage in the knee joint wears down to the point of discomfort or knee instability.


What is the main function of Articular Cartilage?

Articular cartilage has distinctive viscoelastic characteristics. Its main role is to act as a soft, lubricated surface for that lessens the friction upon the subchondral bone. 

What Happens When Articular Cartilage "Wears Down?"

Doctors call the injured areas in the cartilage “lesions.” These injured areas look like potholes in the surface of the cartilage. These lesions can eventually cause pain.


At first, pain is minimal, because the cartilage itself doesn’t have nerves, but when the cartilage wears down a significant amount to the bone, the whole joint could become inflamed and painful.

The Stages of Articular Cartilage Damage

The cartilage in the knee joint wears down over time in everyone. So, this problem is more common in older people or those who have played sports for a sustained period of time.

There are four stages of articular cartilage damage. These four types of articular cartilage defects refer to the severity of the lesion.


  • Grade I defects are weakened cartilage—the cartilage has not worn through, but it has shown signs of softening.

  • Grades II and III describe further weakening of the cartilage.

  • A Grade IV defect lesion is cartilage worn all the way through to the bone.


Sometimes the damaged cartilage detaches from the bone and floats loose in the knee joint. Surgeons refer to these pieces of cartilage as “loose bodies”.

Diagnosing Chronic Articular Cartilage Injuries

Chronic articular cartilage injuries are difficult to diagnose because they don’t immediately cause pain or are the result of a violent knee injury. These injuries start slow and get worse over time. Surgeons will often only discover them when doing other surgical work to repair a ligament.

Do You Need Surgery for Articular Cartilage Injuries?

Articular cartilage injury treatment will usually involve surgery for most cases at some point. With low-grade defects, the doctor may not recommend surgery depending on the patient’s overall health and other factors.

Even Grade IV defects may not be treated with surgery immediately. Surgeons may choose to treat the symptoms—applying ice and other anti-inflammatory measures including injections. Because articular cartilage injuries get worse on their own, most articular cartilage injury treatment involves surgical intervention.


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