Meniscus Tear

Topic Overview

What is a meniscus tear?

A meniscus tear is a common knee injury. The meniscus is a rubbery, C-shaped disc that cushions your knee. Each knee has two menisci (plural of meniscus)-one at the outer edge of the knee and one at the inner edge. The menisci keep your knee steady by balancing your weight across the knee. A torn meniscus can prevent your knee from working right.

See a picture of the knee and the meniscus .

What causes a meniscus tear?

A meniscus tear is usually caused by twisting or turning quickly, often with the foot planted while the knee is bent. These tears can occur when you lift something heavy or play sports. As you get older, your meniscus gets worn. This can make it tear more easily.

See a picture of common meniscus tears .

What are the symptoms?

There are three types of meniscus tears. Each has its own set of symptoms.

With a minor tear, you may have slight pain and swelling. This usually goes away in 2 or 3 weeks.

A moderate tear can cause pain at the side or center of your knee. Swelling slowly gets worse over 2 or 3 days. This may make your knee feel stiff and limit how you can bend your knee, but walking is usually possible. You might feel a sharp pain when you twist your knee or squat. These symptoms go away in 1 or 2 weeks but can come back if you twist or overuse your knee. The pain may come and go for years if the tear is not treated.

In severe tears, pieces of the torn meniscus can move into the joint space. This can make your knee catch, pop, or lock. You may not be able to straighten it. Your knee may feel "wobbly" or give way without warning. It may swell and become stiff right after the injury or within 2 or 3 days.

If you are older and your meniscus is worn, you may not know what you did to cause the tear. You may only remember feeling pain after you got up from a squatting position, for example. Pain and slight swelling are often the only symptoms.

How is a meniscus tear diagnosed?

Your doctor will ask about past injuries and what you were doing when your knee started to hurt. A physical exam will help your doctor find out if a torn meniscus is the cause of your pain. Your doctor will look at both knees and check for tenderness, range of motion, and how stable your knee is. X-rays are also usually done.

You may need to meet with an orthopedic surgeon for more testing. These tests may include an MRI, which can give a clear picture of where a tear is and how serious it is.

How is it treated?

How your doctor treats your meniscus tear depends on several things, such as the type of tear, where it is, and how serious it is. Your age and how active you are may also affect your treatment choices.

Treatment may include:

• Rest, ice, wrapping the knee with an elastic bandage, and propping up the leg on pillows.
• Physical therapy.
• Surgery to repair the meniscus.
• Surgery to remove part of the meniscus.

Small tears at the outer edge of the meniscus often heal with rest and physical therapy. Surgery is a good option for larger tears at the outer edge of the meniscus.

Surgery may not work as well with large tears near the center of the meniscus. But surgery to repair this kind of tear may be the right choice for young people, because it can help the knee work again. Older people may not get the same benefit from this surgery.

How long it takes to recover from surgery will depend on the type of surgery you have. Your recovery plan is likely to include rest, walking, and special exercises.

Health Tools

Health Tools help you make wise health decisions or take action to improve your health.

	Decision Points focus on key medical care decisions that are important to many health problems.
	Should I have an MRI or arthroscopy to diagnose a possible torn meniscus?
	Should I have surgery for my torn meniscus?
	Actionsets are designed to help people take an active role in managing a health condition.
	Meniscus tear: Rehabilitation exercises

Symptoms

Symptoms of a meniscus tear depend on the size and location of the tear and whether other knee injuries occurred along with it. Since there are no nerve endings to the meniscus, pain is due to swelling and injury to surrounding tissues.

With small tears, you may have minimal pain at the time of the injury. Slight swelling often develops gradually over several days. Many times you can walk with only minimal pain, although pain increases with squatting, lifting, or rising from a seated position. These symptoms usually go away in 2 to 3 weeks although pain may recur with bending or twisting.

In a typical moderate tear, you feel pain at the side or in the center of the knee, depending on where the tear is. Often, you are still able to walk. Swelling usually increases gradually over 2 to 3 days and may make the knee feel stiff and limit bending. There is often sharp pain when twisting or squatting. Symptoms may diminish in 1 to 2 weeks but recur with activities that involve twisting or from overuse. The pain may come and go over a period of years if left untreated.

Larger tears usually cause more pain and immediate swelling and stiffness. Swelling can develop over 2 to 3 days. Pieces of the torn meniscus can float into the joint space. This can make the knee catch, pop, or lock. You may not be able to straighten your knee. The knee can also feel "wobbly" or unstable, or give way without warning. If other injuries occurred with the meniscus tear, especially torn ligaments, you may have increased pain, swelling, a feeling that the knee is unstable, and difficulty walking.

Older people whose menisci are worn may not be able to identify a specific event that caused a tear, or they may recall symptoms developing after a minor incident such as rising from a squatting position. Pain and minimal swelling are often the only symptoms.

Pain at the inside of the knee can indicate a tear to the medial meniscus. Pain at the outer side of the affected knee may indicate a tear to the lateral meniscus. See a picture of the medial and lateral menisci .

Exams and Tests

During an examination for a possible meniscus tear, your doctor will ask you about past injuries and what you were doing when your knee started to hurt. He or she will do a physical examination of both knees to evaluate tenderness, range of motion, and knee stability. An X-ray is usually done to evaluate the knee bones.

Your knee may be too painful or swollen for a full exam. In this case, your doctor may withdraw fluid from your joint and inject a numbing medicine (local anesthetic) into the joint. This might relieve your pain enough that you can have an exam. Or, the exam may be postponed for a week while you care for your knee at home with rest, ice, compression, and elevation.¹

Your family doctor or an emergency room doctor may refer you to an orthopedist for a more complete examination. An orthopedist may order a magnetic resonance imaging (MRI) if the diagnosis is uncertain. An MRI typically gives a good picture of the location and extent of a meniscus tear and also provides images of the ligaments, cartilage, and tendons.

An orthopedist may recommend arthroscopy, a procedure used to examine and repair the inside of the knee joint by inserting a thin tube (arthroscope) containing a camera with light through a small incision near the knee joint. With arthroscopy, the orthopedist can directly view and possibly repair the meniscus and other parts of the knee. Surgical repair is commonly done during arthroscopy, although you and your surgeon may decide to have more extensive arthroscopic or open knee surgery later.

Should I have an MRI or arthroscopy to diagnose a possible torn meniscus?

Treatment Overview

There are many things to consider when deciding how to treat your torn meniscus, including the extent and location of the tear, your pain level, your age and activity level, your doctor's preference, and when the injury occurred. Your treatment choices are:

• Nonsurgical treatment with rest, ice, compression, elevation, and physical therapy. This may include wearing a temporary knee brace.
• Surgical repair to sew the tear together.
• Partial meniscectomy, which is surgery to remove the torn section.
• Total meniscectomy, which is surgery to remove the entire meniscus. This is generally avoided, because this option increases the risk for osteoarthritis in the knee.

Whenever possible, meniscus surgery is done using arthroscopy, rather than through a large cut in the knee.

The location (zone) of the tear is one of the most important factors in determining treatment. See a picture of the meniscus zones .

• Tears at the outer edge of the meniscus (red zone) tend to heal well because there is good blood supply. Minor tears may heal on their own with a brace and a period of rest. If they do not heal or if repair is deemed necessary, the tear can be sewn together using dissolvable stitches. This is successful 90% to 95% of the time in this area.²
• The inner two-thirds (white zone) of the meniscus does not have a good blood supply and therefore does not heal well either on its own or after repair. If torn pieces float into the joint space, which may result in a "locked" knee or cause other symptoms, the torn portion is removed (partial meniscectomy) and the edges of the remaining meniscus are shaved to make the meniscus smooth.
• When the tear extends from the red zone into the white zone, there may be enough blood supply for healing. The tear may be repaired or removed. This is something the orthopedic surgeon decides during the surgery.

Also, the pattern of the tear may determine whether a tear can be repaired. Longitudinal tears are often reparable. Radial tears may be reparable depending on where they are located. Horizontal and flap (oblique) tears are generally not reparable. See a picture of different types of tears .

Another factor when considering treatment is that repairs to the lateral meniscus (on the outer side of knee) typically heal better than repairs to the medial meniscus (on the inner side of the knee). See a picture of the lateral and medial menisci .

It is preferable to preserve as much of the meniscus as possible. If the meniscus can be repaired successfully, saving the injured meniscus by doing a meniscal repair reduces the occurrence of knee joint degeneration compared with partial or total removal (meniscectomy). Meniscus repair is more successful in younger people (experts think people younger than 40 years old do best), in knees that have good stability from the ligaments, if the tear is in the red zone, and if the repair is done within the first few weeks after the injury (acute).³

Meniscal repair may prevent degenerative changes in the knee joint. But it has not been proved conclusively that repairing a tear prevents more long-term problems (such as osteoarthritis) than not repairing a tear. Many doctors believe that a successful meniscus repair lowers the risk of early-onset arthritis because it reduces the stress put on the knee joint.

Orthopedists most often perform meniscus surgery with arthroscopy, a procedure used both to examine and then to repair the inside of a joint by inserting a thin tube (arthroscope) containing a camera and a light through small incisions near the joint. Surgical instruments are inserted through other small incisions near the joint. Some tears require open knee surgery.

Should I have surgery for my torn meniscus?

Rehabilitation varies depending on the injury, the type of surgery, your orthopedic surgeon's preference, and your age, health status, and activity demands. Time periods often vary, although in general, meniscus surgery is usually followed by a period of rest, walking, and selected exercises. After you have full range of motion without pain and your knee strength is back to normal, you can return to your previous activity level.

For some exercises you can do at home (with your doctor's approval), see:

Meniscus tear: Rehabilitation exercises.

Other knee injuries, most commonly to the anterior cruciate ligament (ACL) and/or the medial collateral ligament, may occur at the same time as a meniscus tear. In these cases, the treatment plan is different. Typically, your orthopedist will repair your torn meniscus, if needed, at the same time that ACL surgery is done. In this case, the ACL rehabilitation plan is followed. For more information, see the topic Anterior Cruciate Ligament (ACL) Injuries.

Meniscal transplant is an experimental treatment for meniscal tears. It might be a good option for a meniscus that is already weakened or scarred due to previous injury or treatment. In this surgical procedure, a piece of meniscus cartilage from a donor (allograft) is transplanted into the knee.

To be eligible for meniscal transplantation:⁴

• You should be younger than age 40.
• You have pain and swelling in your knee that has not responded to other treatment.
• You have minimal or no arthritis in your knee joint.
• Your knee is well-aligned, meaning you are not bent outward at the knees (bowlegged) or bent inward at the knees (knock-kneed).

Home Treatment

If you have recently injured your knee, follow these first-aid steps to reduce pain and swelling:

• Rest and reduce activity. Avoid motions or positions that cause discomfort. Depending on your injury and pain, your doctor may recommend crutches and a brace.
• Try applying ice to your knee during the first 48 hours after discomfort begins. To avoid harming your skin, place a thin towel between the ice pack and your body, or put a pillowcase over the ice pack. Apply ice 2 to 3 times a day, up to 20 minutes at a time.
• Elevate your knee higher than your heart.
• Take nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, or naproxen to relieve pain and reduce swelling. (Anyone younger than age 20 should not take aspirin because of the risk of Reye syndrome, a central nervous system complication in children and teenagers.)
• Follow your doctor's instructions for rest and rehabilitation of your knee.

If the tear is minor and your symptoms go away, your doctor may recommend a set of exercises to build up your quadriceps and hamstring muscles and increase flexibility and strength. It's important to follow your doctor's guidance to avoid a new or repeat injury.

Every recovery is different and depends on many factors, including your doctor's particular preferences. But here are some general times for returning to activities after surgery.

Other Places To Get Help

Organizations

Related Information

• Anterior Cruciate Ligament (ACL) Injuries
• Knee Problems and Injuries
• Osteoarthritis

References

Citations

1. Smith BW (2002). The acutely injured knee. In JC Puffer, BD Weiss, eds., 20 Common Problems in Sports Medicine, pp. 173-199. New York: McGraw-Hill.

2. Fu FH, Stone DA (2001). Meniscal injuries. In Sports Injuries: Mechanisms, Prevention, Treatment, 2nd ed., pp. 1124-1129. Philadelphia: Lippincott Williams and Wilkins.

3. McMahon PJ, Kaplan LD (2006). Meniscus section of Injuries section of Sports medicine. In HB Skinner, ed., Current Diagnosis and Treatment in Orthopedics, 4th ed., pp. 170-174. New York: McGraw-Hill.

4. Felix NA, Paulos LE (2003). Current status of meniscal transplantation. The Knee, 10(1): 13-17.

Credits