Meniscus is another word for the cartilage in the knee that acts as a shock absorber. You have two of them medial and lateral or inner and outer. They are both C-shaped structures that are made of fibrocartilage.
The meniscus is located between the femur and the tibia or thigh and leg bone. It actually serves many functions in the knee other than shock absorber. It acts as a stabilizer preventing the lower leg from sliding forward on the femur. It also helps to push joint fluid into the surface of the joint to help the cartilage cells survive. The joint has a small coefficient of friction which is the same thing as saying it glides 10 times better than 2 pieces of ice sliding on one another. The meniscus allows the joint fluid to act as a lubricant for the joint and lets the femur glide and roll on the tibia.
It has a blood supply the only reaches the outer third. This will come in handy when we talk about tears and repairing them or trimming them. Listen up CrossFitters, I will let you in on a secret. When we are young it takes a lot of work or a bad injury to tear a meniscus… a bad twist in a soccer game, landing in a squat after a big jump. For people with more experience in life, it takes a lot less to tear them. Some will tear with a sharp twist while maneuvering around an airplane, getting up from playing with the kids, coming down from a rock hiking, PISTOLS. So you can see there is a clear difference between the amount of energy that goes in to the two types of tears. WHY US, older people are saying?
As we age our tissues dehydrate and lose some of their natural elasticity and hydration. Tissues become more brittle and can rip easier than when we were young (sounds like A Killers song). So we see tear patterns that are different and provide the appropriate treatment for each pattern. The treatment depends on location of tear, size of tear, and blood supply to tear. Blood carries oxygen and healing factors that allow tissues to heal. Without it there will be no healing.
People will classically notice swelling in their knee with pain along the inner or outer aspect of their knee. Also people often say it hurts in the back of their knee and confuse it for a hamstring injury. Clicking, buckling, or locking are severe symptoms. Most often it is a pain that is a stabbing knife-like pain accentuated by twisting, pivoting or squatting. I often describe it as a hangnail being pulled on. The tear can get bigger the more it gets pulled on. Front squats, back squats, or pistols can elicit some of these symptoms. Be careful when you are in a deep squat not to rotate or twist as this may pinch the meniscus between the bones and cause a tear
So now on to treatment, basically it is to sew it together or trim the piece that is torn. Repair requires longer recovery (ask some of our CrossFit friends) than trimming. Repair is a 4 month process and trim is a 4-6 week process to get back to feeling good again. When I do arthroscopy on the knee the decision is often made at the time of surgery based on the previous criteria mentioned. Location, size, blood supply, and tear pattern. I only want to take out the bad tissue or piece that is torn and not working anyway. Again like a hangnail I trim it at the base to prevent it from getting bigger and more painful. People often want to know if they can live with a torn cartilage. I unfortunately have seen some cartilage tears do some damage to otherwise healthy appearing knees when it is moving around in the knee causing pain