Your knee is the largest joint in your body and one of the most complex. Because you use it so much, it is vulnerable to injury. Because it is made up of so many parts, many different things can go wrong.
Meniscal tears are among the most common knee injuries. Athletes, particularly those who play contact sports, are at risk for meniscal tears. However, anyone at any age can tear a meniscus. When people talk about torn cartilage in the knee, they are usually referring to a torn meniscus.
Normal knee anatomy
Three bones meet to form your knee joint: your thighbone (femur), shinbone (tibia), and kneecap (patella).
Two wedge-shaped pieces of cartilage act as “shock absorbers” between your thighbone and shinbone. These are called meniscus. They are tough and rubbery to help cushion the joint and keep it stable.
Menisci tear in different ways. Tears are noted by how they look, as well as where the tear occurs in the meniscus. Common tears include longitudinal, parrot-beak, flap, bucket handle, and mixed/complex.
Sports-related meniscal tears often occur along with other knee injuries, such as anterior cruciate ligament tears.
Common types of tears
Sudden meniscal tears often happen during sports. Players may squat and twist the knee, causing a tear. Direct contact, like a tackle, is sometimes involved.
Older people are more likely to have degenerative meniscal tears. Cartilage weakens and wears thin over time. Aged, worn tissue is more prone to tears. Just an awkward twist when getting up from a chair may be enough to cause a tear, if the menisci have weakened with age.
You might feel a “pop” when you tear a meniscus. Most people can still walk on their injured knee. Many athletes keep playing with a tear. Over 2 to 3 days, your knee will gradually become more stiff and swollen.
The most common symptoms of meniscal tear are:
- Stiffness and swelling
- Catching or locking of your knee
- The sensation of your knee “giving way”
- You are not able to move your knee through its full range of motion
Without treatment, a piece of meniscus may come loose and drift into the joint. This can cause your knee to slip, pop or lock.
Physical Examination and Patient History
After discussing your symptoms and medical history, your doctor will examine your knee. He or she will check for tenderness along the joint line where the meniscus sits. This often signals a tear.
One of the main tests for meniscal tears is the McMurray test. Your doctor will bend your knee, then straighten and rotate it. This puts tension on a torn meniscus. If you have a meniscal tear, this movement will cause a clicking sound. Your knee will click each time your doctor does the test.
Because other knee problems cause similar symptoms, your doctor may order imaging tests to help confirm the diagnosis.
X-rays. Although X-rays do not show meniscal tears, they may show other causes of knee pain, such as osteoarthritis.
Magnetic resonance imaging (MRI). This study can create better images of the soft tissues of your knee joint.
How your orthopaedic surgeon treats your tear will depend on the type of tear you have, its size, and location.
The outside one-third of the meniscus has a rich blood supply. A tear in this “red” zone may heal on its own, or can often be repaired with surgery. A longitudinal tear is an example of this kind of tear.
In contrast, the inner two-thirds of the meniscus lacks a blood supply. Without nutrients from blood, tears in this “white” zone cannot heal. These complex tears are often in thin, worn cartilage. Because the pieces cannot grow back together, tears in this zone are usually surgically trimmed away.
Along with the type of tear you have, your age, activity level, and any related injuries will factor into your treatment plan.
If your tear is small and on the outer edge of the meniscus, it may not require surgical repair. As long as your symptoms do not persist and your knee is stable, nonsurgical treatment may be all you need.
RICE. The RICE protocol is effective for most sports-related injuries. RICE stands for Rest, Ice, Compression, and Elevation.
- Rest. Take a break from the activity that caused the injury. Your doctor may recommend that you use crutches to avoid putting weight on your leg.
- Ice. Use cold packs for 20 minutes at a time, several times a day. Do not apply ice directly to the skin.
- Compression. To prevent additional swelling and blood loss, wear an elastic compression bandage.
- Elevation. To reduce swelling, recline when you rest, and put your leg up higher than your heart.
Non-steroidal anti-inflammatory medicines. Drugs like aspirin and ibuprofen reduce pain and swelling.
If your symptoms persist with nonsurgical treatment, your doctor may suggest arthroscopic surgery.
Procedure. Knee arthroscopy is one of the most commonly performed surgical procedures. In it, a miniature camera is inserted through a small incision. This provides a clear view of the inside of the knee. Your orthopaedic surgeon inserts miniature surgical instruments through other small incisions to trim or repair the tear.
Rehabilitation. After surgery, your doctor may put your knee in a cast or brace to keep it from moving.
Once the initial healing is complete, your doctor will prescribe rehabilitation exercises. Regular exercise to restore your knee mobility and strength is necessary. You will start with exercises to improve your range of motion. Strengthening exercises will gradually be added to your rehabilitation plan.
For the most part, rehabilitation can be carried out at home, although your doctor may recommend physical therapy.
Meniscal tears are extremely common knee injuries. With proper diagnosis, treatment, and rehabilitation, patients often return to their pre-injury abilities.
AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice.