The meniscus is the most important cushion you have in your knee.  A meniscus is a c-shaped disc soft cartilage that sits between the femur and the tibia.  If the meniscus is injured and the cushioning is lost, arthritis and pain can occur.

There are many structures within the knee which can cause pain.  By far, one of the most common causes of knee pain is a meniscus tear.  Too many patients walk into my office stating that they have a meniscus tear and wish to have a second opinion, yet when I ask them what is  a meniscus… they are typically not very accurate with their description.  In order for you to make an informed decision about your issue, it is imperative that you have a good understanding of what a meniscus is and what your treatment options are.  Let’s begin.

What is a Meniscus?


What is a Meniscus?
Normal appearance of a meniscus

A meniscus is a crescent or “c”-shaped cartilage disk that’s found in the knee.  There are actually two menisci.  We have one on the inner side of the knee which we call the medial meniscus and one on the outer side of the knee which we call the lateral meniscus.  The menisci serve a very important function in the knee.  Our meniscus  functions as a shock absorber or cushion to minimize the stress on  another type of cartilage that we have in the knee which we call the articular cartilage.  The articular cartilage coats the ends of our bones within a joint.  By protecting the articular cartilage, the meniscus helps prevent the onset of arthritis.    The meniscus also serves to improve stability of the knee.  The meniscus acts like a block stuck behind a tire to prevent a car from rolling.  The less meniscus you have, the more stress the rest of your knee sees and the more unstable the knee may be.

Understanding “what is a meniscus”, enables you to understand how a tear can affect your knee

If a friend tells you they have a “torn cartilage” they are generally referring to a torn meniscus.  When the meniscus is not functioning properly, or it is torn, then you may feel pain with turning, pivoting or twisting.  In addition, you may develop a feeling of instability, or a feeling that the knee wants to give way.  Unfortunately the meniscus does not possess regenerative capabilities.  That means that the tissue  can wear out, because the body does not possess the ability to heal it (like a cut on your skin).   When a tissue has poor regenerative potential, the likelihood of suffering a degenerative or attritional meniscus tear is very high.  Simply stated that means that our tissues can simply wear out and tear from the cumulative stress that we have put on our knee throughout our lives.

In the picture you see a c-shaped meniscus sitting between the end of the femur (top of the picture) and the tibia (bottom of the picture).

So the next time you’re asked, what is a meniscus, you will hopefully know! 🙂

For those who are interested, this video on the anatomy of the knee might help you better answer the question —  what is a meniscus?

Do you believe you may have a meniscus tear?

Keep on learning !  Recommended follow up reading:

Types of meniscus tears

Why do mensicus tears hurt?

Is surgery necessary for all meniscus tears?

Recovery from meniscal surgery?

PRP injections for meniscus tears