The meniscus is a small disc of cartilage that sits between the thigh bone and the shin bone in the deep part of the knee.
The knee joint has several important parts that allow the complex movement involved in rising from a chair, walking, and pivoting. Most of us take these movements for granted because we can do them hundreds of times in a single day without giving them any thought at all. But with a torn meniscus, even getting out of your car or walking across a parking lot can be a real challenge.
The meniscus is a small disc of cartilage that sits between the thigh bone and the shin bone in the deep part of the knee. There are actually two menisci in each knee, one in the inner half of the knee (the medial meniscus), the other in the outer half of the knee (the lateral meniscus). The meniscus serves to help even out the pressure in the knee when you are standing or walking. It also helps the knee move smoothly from being fully extended to a deep bend. As the knee bends, the curved shape of the end of the thigh bone causes the pressure to shift toward the back half of the meniscus.
A meniscus tear can be caused by an injury to the knee but oftentimes is the result of normal wear and tear, leading to weakening of the meniscus tissue over time. Most patients do not recall any specific injury that caused their meniscus tear but notice the pain after physical activity like exercise or working around the house.
The meniscus can tear in a variety of different ways and the treatment may differ depending on the location of the tear and the age of the patient. In general, tears near the outer edge of the meniscus have a better chance of healing, so repair of the meniscus tear, especially in younger patients, may be the best option.
The most common symptoms of a meniscus tear include:
- Pain, especially over the inner half of the knee, worse with pivoting or deep squatting
- Swelling in the knee. The muscles around the knee can hide some of the swelling so the swelling frequently is visible on the upper, outer part of the knee, away from where the pain is felt
- Limited motion. Deep knee bending is often limited with a torn meniscus. Sometimes a tear can limit the ability to fully straighten the knee but this is less common
- Giving Way. A torn meniscus will often cause a feeling of instability or the knee giving out with certain movements. Pivoting is frequently a problem with a torn meniscus.
- Locking, Catching, or Popping. The torn edge of the meniscus can sometimes catch with certain position or movements of the knee and then pop back into place. Sometimes this is a subtle click with mild pain, but other times the knee will get stuck and is very painful.
How do you know if you have a torn meniscus?
Knee pain is very common, whether it is from a job that requires a lot of standing and walking, an exercise program that includes running or jumping, or an injury to the knee. Knee pain alone does not mean you have a torn meniscus. If you have the symptoms listed above, especially if they have continued for more than a week, it is worth getting evaluated by an orthopedic specialist. There are some simple ways to determine if a meniscus tear is likely, including a physical exam and some tests, like a single leg squat or pivoting on one knee, that will help your doctor rule-in or rule-out a torn meniscus. X-rays will not be able to see a torn meniscus but will help your doctor rule out other problems that can cause similar symptoms. An MRI is often useful to determine the location and extent of a torn meniscus.
Next week I will continue this topic with How Do You Treat a Torn Meniscus?