Ask The Physician

Meniscus

Answers to Your Health Questions by Mark A. Pollard, M.D.

Q: What is a meniscus?

A: A meniscus is a “C” shaped wedge of cartilage located between the tibia and the femur in the knee joint. One meniscus is on the inside (medial meniscus) and one meniscus on the outside (lateral meniscus) of the knee. These cartilage wedges serve two purposes in the knee: a shock absorber and stabilizer. The meniscus can become torn and cause pain.

Q: How does a meniscus tear happen?

A: Typically, meniscus tears occur with twisting injuries of the knee. They also commonly occur at the same time as knee ligament injuries (ACL, PCL or MCL).

Q: How do I know if I have a meniscus tear?

A: Most meniscus tears cause pain that localizes to one side of the knee. There is often a history of knee clicking, popping, catching, or locking. A locked knee—a knee that won’t move—is the most serious of these symptoms and should warrant a trip to a doctor as soon as possible. Often, knee swelling will accompany meniscus tears.

Physicians diagnose meniscus tears with a combination of a physical examination, X-rays (which don’t show meniscus tears but do show arthritis) and an MRI. One important item to try to determine is whether the pain is coming from arthritis or from a meniscus tear—both are commonly present in some people.

Q: Can a meniscus tear heal by itself?

A: In most instances, the meniscus does not heal itself. Meniscus tissue has a poor blood supply in adults. Blood supply is critical in tissue healing. Because of the meniscal tissue’s poor blood supply, only a small percentage of tears will heal. In very young people, the chances of healing meniscus is higher.

Q: What is the consequence of removing some of the meniscus?

A: In the short term, relief of symptoms of the meniscus tear should result. Over time, there is a risk for the development of arthritis in the knee after partial meniscus removal. It is difficult to predict who will develop arthritis and who will not.

Q: How is a meniscus tear treated?

A: Every meniscus tear is different. Many things are factored into choosing the appropriate treatment: tear size, tear location, tear shape, patient’s age and the condition of the meniscal tissue. Some tears are treated with repair using stitches or staples to put the torn pieces back together. In very rare situations, meniscal replacement surgery can be performed. For the vast majority of meniscus tears, the best treatment is careful resection of the torn part of the meniscus.

Most of these surgeries can be performed with an arthroscopic procedure—an outpatient surgery typically involving two or three ¼ inch incisions. After these sorts of procedures, patients tend to do very well.