What is the Difference Between the Meniscus and Articular Cartilage?
Many people are confused by the two different types of cartilage within the human knee. Let's talk about it here today. I'm also going to include some quick videos to help you get answers if you are dealing with a meniscus or cartilage issues.
What is the Meniscus?
The meniscus of the knee is C shaped. There is one on the inner side, medial, and one on the outer side, lateral. Think of this as a cushion or sponge between the femur and the tibia. In fact, it is the only cushion we have between these two bones for our entire life.
Unfortunately, the meniscus does undergo some brittleness changes because of blood supply changes during life making it more susceptible to tearing.
— Dr. Sterett
They don’t grow or change in shape or size during the course of our life. Unfortunately, the meniscus does undergo some brittleness changes because of blood supply changes during life making it more susceptible to tearing (A topic I've written about previously). It does not “wear down” and become thinner in life, unlike the articular cartilage which does eventually wear down.
Here are some videos about meniscus tears. Once you are done with those, keep scrolling to learn about Articular Cartilage.
Video: Meniscus Tears
Video: What Does a Meniscus Tear Feel Like?
Video: What Causes a Meniscus Tear?
what is articular cartilage?
aids the "gliding function"
When you see the smooth, shiny stuff on the end of a chicken bone, that is akin to our articular cartilage. VERY different than the meniscus, but still called cartilage.
Think of this as a cap of low friction paint covering the end of a bone within the joint.
The function of articular cartilage is to decrease the friction when a joint is moving, giving it more of a gliding function.
It is not like the sponge cushion of the meniscus or separate from the bone. The whole function of articular cartilage is to convert a cobblestone road into a marble drive. It becomes that slick.
Articular Cartilage and Arthritis
caused by lack of articular cartilage
Articular cartilage is much like the treads on your tires. They can get thinner from normal wear and tear after many years, or they can suddenly have some damage after running over something.
The LACK of articular cartilage in a joint is called arthritis, plain and simple. It really doesn’t matter whether the lack of cartilage is from wear and tear, which is called osteoarthritis, or from an injury where the articular cartilage is knocked off, which is called post traumatic arthritis.
Articular Cartilage and Inflammatory Arthritis
If your own body is attacking the articular cartilage, like it does with rheumatoid arthritis, this is called inflammatory arthritis. There is lots more to talk about with cartilage health and cartilage injuries, both prevention and treatment options.
For now, remember that, just like the type of driving we do affects how long our tires last, the type of sports we participate in will affect both the risk of injury to the meniscus cartilage, and the wear sustained by the articular cartilage.
Meniscus and Articular Cartilage: Hope That Clears it Up!
Nobody was trying to confuse us with having two different types of cartilage within the knee, its just the way it is. So in case you find yourself on a game show and the million dollar question is "what are the two types of cartilage found in the knee"... well now you know!