The meniscus is a rubbery pad of tissue that cushions the joint between the lower leg and the thigh. When it gets torn, the tear can interfere with movement at the joint. This can sometimes cause the knee to lock up or catch. A meniscal tear can cause pain and swelling.
How Tears Occur
Athletes who cut in front of one another on the field or court can sometimes twist their knee, tearing their meniscus. In older people, the meniscus is often weakened by many years of wear and tear. In this case, a tear can occur during minor movements, such as turning around or standing up wrong.
Old Meniscii vs Young Meniscii
The meniscus has zones, or areas, that are quite different from one another. In the outer zone there is a good blood supply. This is known as the “red zone”. In the inner zone there is not a good blood supply. This is known as the “white zone”. Without good blood flow to the damaged area, a wound cannot heal. This is true of every injury, including a torn meniscus.
As we get older, the blood flow to the inner meniscus decreases. This means that a meniscus tear in a younger person may be treated differently than a meniscus tear in an older person.
How is a Meniscal Tear Diagnosed?
When a provider suspects a torn meniscus, he or she will take a history to find out what situation led to the injury. After the history, a physical exam will be performed.
The symptoms of a torn meniscus can be caused by other types of knee injuries. Because of this, imaging tests are usually required in order to verify a diagnosis. The first imaging test is usually an x-ray of the knee. An x-ray won’t show the torn meniscus itself, but it can show the general condition of the knee.
After an x-ray is taken, it may be necessary to perform an MRI, or Magnetic Resonance Imaging Scan to see exactly what the problem is.
How is a Meniscal Tear Treated?
Once a meniscus tear has been diagnosed, the provider will decide how best to treat it. Conservative treatment usually involves rest, ice, compression (or wrapping with a pressure bandage) and elevation (or keeping your knee raised up higher than your heart). Non-steroidal anti-inflammatory medications such as ibuprofen may help with swelling.
If surgery is necessary, a surgeon may repair the tear in your meniscus with sutures. If there is not enough blood flow to the area, the torn part of the meniscus may simply be removed. Both types of surgery are usually done using arthroscopy, which involves putting a tiny camera inside the knee. The camera projects images from inside the knee onto a screen. The surgeon then inserts narrow instruments to perform surgery using the image on the screen for guidance.
Recovery from the removal of the torn part of a meniscus can take 4 to 6 weeks. The patient is able to put full weight on the knee almost immediately. Recovery from a meniscal repair can take 3 to 6 months.