Meniscus Tear

What is a Meniscus Tear? How is it diagnosed?

What is a Meniscus Tear?

A meniscus tear is a tear or rip in either of the two menisci of your knee, C-shaped portions of toughened cartilage that help cushion and absorb shock within the knee joint. The medial meniscus is located on the inner side of the knee joint while the lateral meniscus is located on the outer side of the knee joint. The menisci can be torn from sudden twisting injuries with the foot planted on the ground that can occur with slips and falls or running, cutting, and pivoting motions with athletic activities. Meniscus tears can also be degenerative and occur from age-related wear-and-tear where the menisci become damaged over time.

How is it diagnosed?

History & Physical Exam

A thorough history and physical examination by your healthcare provider can help determine whether you have a meniscus tear. Your healthcare provider will ask you questions about your symptoms and how and when your symptoms began to get a clearer picture of how your injury occurred. 

In addition to discussing your medical history, your healthcare provider will perform a physical examination to assess your knee for pain, swelling, and mobility. Your healthcare provider will feel the soft tissues around your knee to see if anything is tender to the touch, and bend and straighten your knee to see if your range of motion is affected or if certain motions are painful.

Your healthcare provider will also test the strength of your leg muscles and examine your ability to walk and move your knee joint. If a meniscus injury is suspected, your healthcare provider will likely perform specialized tests to examine the integrity of your menisci and overall knee stability. These tests include:

• McMurray’s Test: Your healthcare provider will have you lay down on your back with your knee bent. Your healthcare provider will then hold your foot and twist your lower leg, first internally rotating your leg inward while pulling outward against your knee joint before extending your knee all the way. Your healthcare provider will then bend your knee again and externally rotate your leg outward while pushing inward against your knee joint before extending your knee all the way again. A positive test in which you feel pain, clicking, or locking of your knee when your healthcare provider is trying to extend your knee suggests an injury to your meniscus, either to your lateral meniscus (symptoms with internal rotation) or your medial meniscus (symptoms with external rotation).
• Apley’s Grind Test: Your healthcare provider will have you lay down on your stomach while holding your leg with your knee bent to 90 degrees. Your healthcare provider will then hold your foot and twist your lower leg inward and outward while first applying a compression force to press your leg down into the table. This procedure will then be repeated while your healthcare provider applies a distraction force pulling your leg up from the table as your leg is rotated inward and outward. A positive test in which you feel pain, clicking, or locking of your knee with compression and less discomfort with distraction suggests an injury to your meniscus, either to your lateral meniscus (symptoms with internal rotation) or your medial meniscus (symptoms with external rotation).
• Thessaly’s Test: While standing on one leg and holding on to your healthcare provider’s hands for support, you will bend your knee to 5 degrees and twist your leg inward and outward while maintaining your foot planted on the ground. You will then repeat this procedure with your knee bent to 20 degrees. A positive test in which you feel pain, clicking, or locking of your knee suggests an injury to your meniscus, either to your lateral meniscus (symptoms with internal rotation) or your medial meniscus (symptoms with external rotation).

These tests are stronger indicators of meniscus injuries when performed all together rather than in isolation.

• Longitudinal (Vertical): a tear through the length of the meniscus in a front to back direction, dividing the meniscus into left and right halves, often co-occurring with ACL tears
• Radial: a tear through the width of the meniscus from the inner border into the center of the meniscus
• Horizontal: a tear through the height of the meniscus in a plane parallel to the ground, dividing the meniscus into top and bottom halves, often occurring without trauma and associated with the development of knee osteoarthritis 

If more than one tear type is involved, a meniscus tear will be classified as complex.

If a meniscus tear is severe, it can progress to a more involved type of tear, which include:

• Bucket Handle: progression of a longitudinal tear, causing the inner portion of the meniscus to separate away from the rest of the meniscus, forming an appearance like a bucket handle that causes a portion of the meniscus to move into the center of the knee joint
• Parrot Beak: progression of a radial tear that causes a large pointed edge of the inner portion of the meniscus to separate from the rest of the meniscus, protruding into the center of the knee joint
• Flap: progression of a horizontal tear in which the torn portion of the meniscus flaps upward into the knee joint

Imaging 

While a thorough medical history and physical examination may be able to provide enough information to suggest that your meniscus is torn, imaging studies may be performed to ultimately confirm a diagnosis of a meniscus tear. Different imaging methods can be used to examine the tissues and structures of your knee, which include:

• X-Ray: An x-ray is a 2-dimensional image produced by radiation that examines the structure of your bones. Your healthcare provider may order an x-ray to make sure that you do not have a broken bone or to check for signs of arthritis. Because x-rays only clearly produce images of bones, they cannot be used to diagnose a meniscus tear.
• MRI: An MRI, or magnetic resonance imaging, is a 3-dimensional imaging scan that is produced by magnetic fields. MRIs more clearly illustrate soft tissues of the body and can be used to assess the integrity of your menisci and surrounding structures like ligaments, tendons, and cartilage. While an MRI is not always necessary, it is often ordered to confirm a diagnosis of a meniscus tear.

Meniscus Tear Treatment Options (Surgical vs Non-Surgical)

The way in which you tore your meniscus will influence whether surgical or non-surgical treatment options will be needed to rehabilitate your knee. Most non-traumatic meniscus tears are degenerative and do not require surgery, especially in people ages 50 years and older. If symptoms like severe pain, knee instability, and locking significantly impact daily functions and persist after trying non-surgical treatment options, a menisectomy may then be considered to help treat a degenerative meniscus tear. Many degenerative meniscus tears that occur over time with age are asymptomatic and typically do not need surgery. Additionally, degenerative meniscus tears that occur alongside knee osteoarthritis rarely require or benefit from surgery.

For traumatic meniscus tears, especially in younger patients and athletes, surgery may be needed more frequently, although conservative non-surgical treatment options are often tried first. If surgery is needed, the type of surgical procedure (meniscectomy vs meniscus repair) performed will vary depending on the type of tear and where within your meniscus the tear is located. Different sections of both the medial meniscus and lateral meniscus have different capacities to heal due to differences in blood supply between the middle portions and outside borders and will influence whether a portion of the meniscus will need to be repaired or removed. The size and type of tear will also affect whether a meniscectomy or meniscus repair is more appropriate.

Surgery – Meniscectomy and Meniscus Repair

Conservative treatment like rest, pain management, and physical therapy are often trialed first before undergoing surgery for a meniscus tear unless there is a dislodged meniscus portion. A dislodged meniscus portion can get stuck in the knee joint and will cause it to lock, preventing the knee from fully extending. In these cases, surgery is recommended right away to restore function of the knee joint.

If surgery for your meniscus tear is needed, you may either have a meniscectomy or a meniscus repair performed depending on the type of tear and where within your meniscus the tear is located. With a menisectomy, a portion of the torn meniscus will be surgically removed. With a meniscus repair, the torn meniscus portions will be surgically sewn back together. 

If you have a non-traumatic degenerative meniscus tear that requires surgery, a menisectomy will generally be performed as a degenerated meniscus has a poor capacity to heal with a meniscus repair. If you have a traumatic meniscus tear that requires surgery, the type and location of the tear will influence whether you have a meniscectomy or meniscus repair performed. A meniscectomy is performed much more frequently in general, especially for radial and horizontal tears, while a meniscus repair may be performed for longitudinal tears.

Tears located in the more central portions of the menisci have a decreased likelihood to heal due to a significant reduction in blood supply. If tears in these regions do not improve with conservative rehabilitation, a menisectomy is typically performed to remove the torn meniscus fragments. The outer 20-30% of the medial meniscus and outer 10-25% of the lateral meniscus, however, contain a rich blood supply. Tears in these regions are more likely to heal with conservative rehabilitation or do well with a surgical meniscus repair. 

Both a meniscectomy and a meniscus repair are performed through a knee arthroscopy, a minimally invasive surgical procedure to repair or remove damaged structures within the knee joint. During your operation, your surgeon will use an arthroscope, a tool the size of a pencil with a camera and light attached, to view the inside of your knee joint while using surgical tools to either remove or repair part of your meniscus.

If you are generally healthy, the surgery will likely be performed in the outpatient surgical setting, so you will not have to stay overnight at a hospital. 

Non-Surgical Management of Meniscus Injury

Non-surgical management for a meniscus tear involves carefully structured and progressive physical therapy to rehabilitate your knee to decrease pain and swelling, restore normal knee joint range of motion, and improve the strength of the muscles that control your hip, knee, and ankle joints to stabilize your leg. 

Resting your knee from physical activity and use of ice, elevation, and compression can also be used to help alleviate pain and swelling. Your healthcare provider may prescribe you medication like nonsteroidal antiinflammatory drugs (NSAIDs) to help control your pain, and may consider giving you a cortisone injection into your knee to decrease pain and inflammation.

Many meniscus tears are degenerative over time and do not require surgery, especially if they are asymptomatic. Conservative measures like rest, pain management, and physical therapy are especially successful if meniscus tears measure less than 5mm and are located within the outer borders of the menisci as these areas have a greater likelihood to heal. 

Meniscus Tear FAQs

General

How common is a meniscus tear?

A meniscus tear is a very common knee injury with an exact incidence rate that is difficult to determine based on the fact that not all meniscus tears are symptomatic nor require surgical treatment. For meniscus tears that do require surgery, about 50,000-60,000 meniscectomies and 3,000-3,500 meniscus repairs are performed each year in the United States.

Treatment Decision

Who is not a good candidate for surgery?

People with significant comorbidities such as heart and lung problems and bleeding disorders may not be healthy enough to undergo any type of surgery and are usually not good candidates for a meniscectomy or meniscus repair. People with meniscus tears that are asymptomatic or that cause mild to moderate symptoms are also not good candidates for surgery as they are likely to benefit from physical therapy and other conservative treatment options. You may only be a candidate for surgery if your symptoms are severe and significantly limit your daily functions, which most often occur in people 40 years of age or younger with traumatic meniscus tears.

Can I wait to have surgery?

Because most meniscus tears are degenerative over time and do not require surgery, a meniscectomy or meniscus repair should not be performed until other treatment methods like pain medications, physical therapy, and cortisone injections have been tried for several weeks or months. If symptoms like severe pain and knee instability significantly limit your ability to walk and move your knee joint after trying other treatment options, surgery may be recommended.

What’s the difference between a meniscectomy and meniscus repair? Which one is more common?

A menisectomy involves cutting away a torn portion of your meniscus while a meniscus repair involves using stitches to repair the torn pieces of your meniscus back together. Because the majority of each meniscus does not have a good capacity to heal, a menisectomy is performed more frequently than a meniscus repair.

After Surgery

Can I shower or take a bath?

You should avoid taking a bath or shower for the first two to five days after surgery to protect your incisions. Avoid submerging your leg in water during the first two to three weeks after surgery to decrease the risk of your incisions reopening. 

Can I go up and down the stairs?

You will be able to go up and down the stairs although you may have some limitations at first as you may have to wear a knee brace and use crutches to walk around until your knee has gained enough strength and stability. Your physical therapist will instruct you in the proper sequencing up and down the stairs with your crutches and leg brace, which will involve leading with the unoperated leg when going up the stairs and leading with the operated leg when going down the stairs.

How long will I need to use crutches?

Crutches may be needed for 0-2 weeks after a meniscectomy or up to 4-6 weeks after a meniscus repair.

When can I return to work/school?

If your job or school setting is generally sedentary, you can likely return to work or school within one to two weeks after surgery. For jobs that require prolonged standing, walking, or bending, you may not return to work until 6-12 weeks or more depending on your progress with rehabilitation and how physically demanding your job duties are.

How can I minimize scarring?

You can minimize scarring by avoiding picking at your surgical incisions and leaving your stitches or steri-stris in place until they naturally come off. Keeping your incisions clean and dry will also help avoid infection which can delay healing and worsen scarring.

Can I re-injure my meniscus? If so, how can I prevent re-injury?

Re-injuring your meniscus is possible if you try to return to too much activity too soon without strengthening your leg muscles enough or not allowing your meniscus enough time to heal. To prevent re-injury, consistent physical therapy visits and progressive exercises over several weeks are crucial to maximize the strength and stability of your meniscus.