An Overview of Meniscus Tear

The meniscus is a type of C-shaped cartilage that sits within your knee joint between your thigh bone and shin bone. Each knee joint has two mensici—one on the outside of the knee (called the lateral menisci) and one on the inside of the knee (called the medical menisci).

The medial and lateral menisci act as shock-absorbers and also provide cushioning and stability to the knee, which is why any tear or damage to a meniscus results in pain, swelling, and sometimes, a feeling that the knee is giving out. While knee meniscus tears are common in athletes, older people are also at risk.

In order to diagnose a meniscus tear, your healthcare provider will perform a medical history, physical examination, and order one or more imaging tests.

Once diagnosed, your healthcare provider will help you decide on the best treatment plan, which often entails non-surgical options like taking anti-inflammatory medication and undergoing physical therapy. If your symptoms persist despite conservative measures, your healthcare provider may recommend surgery.

Symptoms

A meniscus tear results in pain in the front of the knee, either in the middle of the knee (from a medial meniscus tear, which is more common) or the side of the knee (from a lateral meniscus tear). Interestingly, as is often the case with a torn meniscus, a person can still walk and even continue to play their sport right after the injury. However, within a day or two, the knee becomes uncomfortably swollen and stiff.

Along with pain, swelling, and stiffness, depending on the type and severity of the injury, other symptoms may include:

• A catching or clicking sensation when walking
• An inability to bend or fully extend the knee
• A feeling of the knee giving way (knee instability)

Causes

Most commonly, a meniscus tear results from an acute injury to the knee, often from a sudden twist of the knee while squatting during a sports activity. Examples of sports that increase a person's risk for a menisci tear include:

• Soccer
• Football
• Basketball
• Baseball
• Skiing
• Wrestling

But meniscus tears can also occur due to age-related degenerative (wear-and-tear) changes (knee osteoarthritis). As people age, their menisci weaken and become more brittle and prone to damage. Everyday movements like getting up improperly from a chair can be enough to cause a meniscus tear.

Diagnosis

The diagnosis of a meniscal tear requires a medical history, physical examination, and imaging.

Medical History

During your healthcare provider's appointment, he will ask you several questions about your knee pain. Examples of such questions include:

• Where exactly is your knee pain located?
• Did your knee swelling come on suddenly or did it gradually develop over days?
• Are you experiencing any other symptoms besides pain and swelling, like your knee giving out or an inability to bend or extend your knee?
• Have you experienced any trauma or injury to the knee?
• Do you have a known history of knee osteoarthritis?

Physical Examination

After taking a medical history, your healthcare provider will perform a physical exam in which he will inspect, press on, and move your knee joint to evaluate for swelling, tenderness, its range of motion, and clicking within the joint. Your healthcare provider will also check your leg muscle strength and assess your gait and ability to fully extend or bend your knee on your own.

One classic test used to assess for meniscus damage is called the McMurray test.

Imaging

Even if your healthcare provider suspects a meniscus tear, he may first order an X-ray of your knee to assess for any concomitant bone breaks or other signs of knee pain, like osteoarthritis.

In general, though, the gold standard or prime test for diagnosing and evaluating a meniscus tear is a magnetic resonance imaging (MRI) of the knee.

Differential Diagnoses

Other knee-related diagnoses may cause pain and symptoms that mimic that of a meniscus tear. Two classic examples include:

Anterior Cruciate Ligament Injury

An anterior cruciate ligament (ACL) tear may occur when an athlete suddenly changes direction or lands from a jump incorrectly. Sometimes an ACL tear occurs along with a medial meniscal tear.

Such injuries can often be distinguished with a good history. An ACL tear may cause a "popping" sound or sensation and will often cause immediate swelling. In contrast, the swelling of an isolated medial meniscus tear tends to develop gradually over the course of one to two days. An MRI can confirm one or both diagnoses.

Collateral Ligament injury

Collateral ligament injuries may also cause knee pain and swelling, like meniscus tears. These may involve the medial collateral ligament (located on the inside of the knee) or the lateral collateral ligament (located on the outside of the knee).

Ligament injuries tend to occur as a result of a direct blow to the knee (like during a football tackle), and similar to an ACL tear, they may occur in combination with a meniscus tear.

A detailed physical exam can help distinguish between knee ligament and meniscus injuries. For example, the pain of a medial or lateral collateral ligament injury is felt directly over the affected ligament, while with meniscus tears, the pain is felt along the knee joint plane, either medially or laterally. Moreover, with meniscus tears, the pain is usually significantly worsened by fully extending or bending the knee.

As with an ACL tear, an MRI can sort out a collateral ligament versus a meniscus injury.

Treatment

While you may presume that surgery is needed for the treatment of a meniscus tear, this is not usually the case. Most of the time, non-surgical therapies are all that is needed to heal the meniscus.

Non-Surgical Options

The initial treatment of a meniscus tear is the R.I.C.E. protocol:

• Rest with modified activity.
• Apply ice or a cold pack to your knee for 15- to 20-minute sessions, several times a day.
• Compress your knee with a brace or knee sleeve to prevent additional swelling.
• Elevate your leg above your heart while icing it or whenever resting/relaxing.

In order to further reduce pain and swelling, your healthcare provider may also advise you to take an oral nonsteroidal anti-inflammatory drug (NSAID). Sometimes, a steroid (cortisone) injection into the knee joint is given to reduce inflammation and ease pain.

After the R.I.C.E. protocol and a proper diagnosis by your healthcare provider, physical therapy usually follows.

Note, though, that non-surgical treatments are nearly always the ideal choice for treating meniscus tears that occur as a result of degenerative changes. This is because studies have found that long-term results are not improved with surgery for people with a degenerative meniscus tear.

For instance, one study found that there was no clinically relevant difference between those who underwent a supervised 12-week exercise therapy program versus those who underwent surgery for degenerative medial menisci tears. In fact, the participants in the exercise therapy program had an improvement in thigh muscle strength compared to those who had surgery—a positive outcome.

Surgery

Surgery has the best results when the primary symptoms of the meniscus tear are mechanical. This means that the meniscus tear is causing a catching or locking sensation of the knee. In other words, when the meniscus tear is causing pain only, the results of surgery may not be as reliable. 

There are three types of surgery used to treat a meniscus tear:

Arthroscopic Meniscectomy

A meniscectomy is a procedure to remove the torn portion of the meniscus. This procedure is far more commonly performed than a meniscus repair. The meniscectomy is done to remove the damaged portion of the meniscus while leaving as much healthy meniscus as possible. The meniscectomy usually has a quick recovery and allows for the rapid resumption of activities.

Meniscus Repair

A meniscus repair is a surgical procedure done to repair the damaged meniscus. The meniscus repair can restore the normal anatomy of the knee and has a better long-term prognosis when successful. However, the meniscus repair is a more significant surgery, the recovery is longer, and, because of limited blood supply to the meniscus, it is not always possible.

Meniscus Transplant

Meniscus transplantation consists of placing the meniscus from a deceased donor patient into an individual who has had their meniscus removed. The ideal patient for a meniscus transplant is someone who had their meniscus removed and subsequently begins to develop knee pain.

Meniscus transplant is not performed for an acute meniscus tear, but rather when removal of the entire meniscus has caused persistent pain in the knee.

Long-Term Prognosis

When you tear the meniscus of your knee, the shock absorbing ability of the joint is threatened. Because of this, there is an increased risk of developing damage to the cartilage surface of the knee joint. Loss of the meniscus places more of a burden on the cartilage surfaces of the joint, and they are more likely to develop wear-and-tear arthritis.

The upside is that you can make lifestyle changes to decrease your risk of developing arthritis after having sustained a meniscus tear. Some of these lifestyle preventive strategies include:

• Weight loss
• Low-impact exercise
• Prevention of further trauma to the joint

A Word From Verywell

Not every torn meniscus is the same, and not every meniscus tear requires the same type of treatment. Moreover, meniscus tears are very common, so try not to get discouraged if you injure yours. With proper physical therapy and care, most people heal well and return to their desired sports and activities.

Read more about meniscal cysts.