The offensive line had been opening big holes in the defense for Dylan to run through all game, and he'd already scored two touchdowns as a result. But on one play a defender closed the hole and stood him up until more defenders came and helped. As Dylan was forced to the ground, his knee got caught under him and bent awkwardly, and he felt a little pop.

The team's trainer told Dylan to take the rest of the game off and ice his knee. The next day his knee was still tender and a little swollen, so he went to see a doctor. The doctor asked questions and examined the knee. He sent Dylan for an MRI scan, and when Dylan came back for the results he learned he'd torn his meniscus and might need surgery to fix it.

What Is a Meniscus Tear?

Your knee is composed of three bones: the thighbone (femur), the shinbone (tibia), and the kneecap (patella), as well as the soft tissue that connects them. Between your femur and your tibia are two C-shaped discs of cartilage that act as shock absorbers for the bones and help keep your knee stable. These are your menisci (plural of meniscus), and they can be torn, particularly if the knee twists suddenly while it is bent.

Viewed from the front or back, the meniscus is wedge shaped. This shape helps keep the rounded surface of your femur from sliding off the flat top of your tibia. The outer edges of this wedge receive a good supply of blood, and tears in this part of the meniscus heal well on their own. The inner part of the meniscus, however, has no direct blood supply. Tears in this area can require surgery to correct.

A torn meniscus is a common sports injury, particularly in contact sports like football and hockey. Meniscus tears can range from minor to severe, depending on the extent of the damage, and they can make it difficult for the knee to function properly.

What Are the Symptoms of a Meniscus Tear?

The symptoms of a torn meniscus will vary depending on the severity of the tear. Someone who gets a minor tear may only have slight pain and swelling that goes away after 2 or 3 weeks.

Moderate to severe tears also might cause these symptoms:

• a "pop" in the knee when the tear occurs
• pain in the center or side of the knee, especially when twisting the knee or squatting. This will usually go away after a couple of weeks but can come and go for much longer if the tear is not treated.
• swelling and stiffness in the knee that gets worse over the first 2 or 3 days after the injury occurs
• limited range of motion
• the knee feeling as if it is locking or popping when bending; it might not straighten
• the knee feeling like it is giving way without warning

How Is a Meniscus Tear Diagnosed?

If you see a doctor about pain in your knee, he or she will ask how you injured it and what it feels like. The doc will also review your medical history to see if the pain might be caused by something other than a torn meniscus.

The doctor will do a thorough examination of your knee to see if you have any tenderness in the area where your meniscus sits. One test that doctors use to tell if pain is being caused by a meniscus tear is called the McMurray test. It involves simply bending your knee, then straightening it and rotating it.

The doctor also might order an X-ray to check for any degenerative or arthritic conditions that can cause knee pain or a magnetic resonance imaging (MRI) scan to get a better look at the soft tissue of your knee.

What Causes a Meniscus Tear?

For teens, meniscus tears usually happen because of an injury. (Meniscus tears also can be caused by degeneration of the tissue, but that's most commonly seen in older people as the menisci become brittle and less flexible with age.)

Younger people usually tear their menisci as a result of twisting or turning the knee while it is bent and the foot is firmly planted. Causes of this type of tear include:

• lifting heavy objects
• making sudden changes in direction or slowing or stopping quickly, as can happen in sports like soccer, baseball, basketball, tennis, and racquetball
• direct impact in a contact sport, such as football, hockey, or rugby, where the knee may be forced to twist or turn awkwardly
• excessive strain on the knees during a fall, as can happen in sports like skiing or snowboarding

Meniscus tears often happen along with other knee injuries such as ligament tears.

How Can You Prevent a Meniscus Tear?

Because they generally happen without any warning, meniscus tears can be hard to prevent. You can reduce your risk, though, by taking these precautions:

• Get regular exercise, including strength training for your leg muscles. Strong leg muscles help stabilize and protect the knee.
• Always warm up and stretch properly before playing sports or engaging in any strenuous activity involving your legs.
• Give your muscles plenty of time to rest and recover between activities.
• Get the right footwear for your sport, and keep shoes, boots, or skates laced up tight while you play.
• Learn and use the proper techniques for your sport.
• If you've previously had another knee injury, a brace or wrap can give your knee added support.

How Should You Treat a Meniscus Tear?

With minor tears, especially on the outer part of the meniscus where there is a good supply of blood, surgery generally isn't necessary, and the tear should heal on its own fairly quickly. Treatment for this sort of tear can include the following:

• Use the RICE formula:
  • Rest: Stop doing the activity that caused the injury, and give your knee plenty of time to rest. In some cases, this may involve using crutches to keep weight off your knee while it recovers.
  • Ice: Apply ice or a cold compress to your knee several times a day for 20 minutes at a time until the pain and swelling subside. Make sure you don't apply ice directly to the skin, as this can cause tissue damage.
  • Compression: Use an elastic compression bandage to keep swelling down and help support your knee.
  • Elevation: Lie down and put pillows under your knee to raise it above the level of your heart. This will help keep swelling to a minimum.
• Take anti-inflammatory medications. Painkillers such as acetaminophen and ibuprofen can help relieve pain and reduce swelling in the affected area.
• If your doctor prescribes it, do physical therapy. PT can help you strengthen your leg muscles, stabilize your knee, and get your knee back to its full range of motion and flexibility.

For severe tears or tears that don't respond to other forms of treatment, a doctor may have to perform surgery. Usually, this will be in the form of arthroscopic surgery, where a small camera is inserted into the knee to help surgeons see what they're doing without having to open the knee up.

Some meniscus tears can be repaired through surgery. Other times, the surgeon will trim away the torn piece of the meniscus to keep it from affecting the knee's functionality. Following the surgery, the doctor may put your knee in a cast or brace to immobilize it while it heals, and you might need to use crutches for a while.

As with any sports injury, the key to healing meniscus tears — no matter how minor — is not to get back into play too quickly. Your body (and performance) will be stronger if you wait until your doctor gives you the OK to get back in the game.

Reviewed by: Kathleen B. O'Brien, MD
Date reviewed: April 2011