The meniscus is a piece of cartilage that provides a cushion between your femur (thighbone) and tibia (shinbone). There are two menisci in each knee joint.
They can be damaged or torn during activities that put pressure on or rotate the knee joint. Taking a hard tackle on the football field or a sudden pivot on the basketball court can result in a meniscus tear.
You don’t have to be an athlete to get a meniscus tear, though. Simply getting up too quickly from a squatting position can also cause a meniscal tear. According to Boston Children's Hospital, more than 500,000 meniscal tears take place in the United States each year.
Depending on the severity of your injury, treatment options can vary from at-home remedies to outpatient surgery. You can help prevent this injury by doing exercises that’ll strengthen your leg muscles and using proper techniques during contact activities or sports.
The meniscus can be torn during activities that cause direct contact or pressure from a forced twist or rotation. A sudden pivot or turn, deep squatting, or heavy lifting can lead to injury. Many athletes are at risk for a meniscus tear.
Sports that require sudden turns and stops may put you at higher risk for meniscus tears. Some of these sports include:
According to Boston Children's Hospital, meniscus tears are growing increasingly common in children. This is because children are participating in organized sports at an earlier age. Additionally, when focusing on just one sport, a child is more likely to experience a meniscus tear. The same is true for adolescents who participate in competitive sports.
The meniscus weakens with age. Tears are more common in people over the age of 30. Movements like squatting or stepping can lead to injury in someone with weak menisci.
If you have osteoarthritis, you’re at higher risk of injuring your knee or tearing your meniscus. Osteoarthritis is a common joint disorder involving pain and stiffness in your joints caused by aging and wear and tear.
When an older person experiences a meniscus tear, it’s more likely to be related to degeneration. This is when the cartilage in the knee becomes weaker and thinner. As a result, it’s more prone to tear.
When a meniscus tear occurs, you may hear a popping sound around your knee joint. Afterward, you may experience:
- pain, especially when the area is touched
- difficulty moving your knee or inability to move it in a full range of motion
- the feeling of your knee locking or catching
- the feeling that your knee is giving way or unable to support you
You may also experience a slipping or popping sensation, which is usually an indication that a piece of cartilage has become loose and is blocking the knee joint.
Contact your doctor if you experience any of these symptoms and they persist for more than a few days or occur after your knee has been injured. Call your doctor immediately if your knee locks and you’re unable to bend your knee after straightening it.
After you discuss your symptoms with your doctor, they’ll examine your knee and test your range of motion. They’ll look closely at the spot where the meniscus is along your joint.
Your doctor also may perform a McMurray test to look for a meniscal tear. This test involves bending your knee and then straightening and rotating it. You may hear a slight pop during this test. This can indicate a tear of the meniscus.
Imaging tests may be ordered to confirm a tear of the meniscus. These include:
This test won’t show a meniscus tear. However, it can be helpful to determine if there are any other causes of your knee pain, like osteoarthritis.
An MRI uses a magnetic field to take multiple images of your knee. An MRI will be able to take pictures of cartilage and ligaments to determine if there’s a meniscus tear.
While MRIs can help your doctor make a diagnosis, they aren’t considered 100 percent reliable. According to a study from 2008 published in the Journal of Trauma Management & Outcomes, the MRI’s accuracy for diagnosing lateral meniscus tears is 77 percent.
Sometimes, meniscus tears may not show up on an MRI because they can closely resemble degenerative or age-related changes. Additionally, a doctor may make an incorrect diagnosis that a person has a torn meniscus. This is because some structures around the knee can closely resemble a meniscus tear.
However, using an MRI has helped reduce the need for arthroscopy in some people.
An ultrasound uses sound waves to take images inside the body. This will determine if you have any loose cartilage that may be getting caught in your knee.
If your doctor is unable to determine the cause of your knee pain from these techniques, they may suggest arthroscopy to study your knee. If you require surgery, your doctor will also most likely use an arthroscope.
With arthroscopy, a small incision or cut is made near the knee. The arthroscope is a thin and flexible fiber-optic device that can be inserted through the incision. It has a small light and camera. Surgical instruments can be moved through the arthroscope or through additional incisions in your knee.
After an arthroscopy, either for surgery or examination, people can often go home the same day.
Initially, you should treat the knee injury with conservative techniques that include rest, ice, compression, and elevation, or the RICE method:
- Rest your knee. Use crutches to avoid any weight bearing on the joint. Avoid any activities that worsen your knee pain.
- Ice your knee every three to four hours for 30 minutes.
- Compress or wrap the knee in an elastic bandage to reduce inflammation.
- Elevate your knee to reduce swelling.
You shouldn’t put your full weight on your injured knee if it’s painful. Your doctor may recommend physical therapy to strengthen the muscles surrounding your knee.
Physical therapy can help reduce pain and increase your knee mobility and stability. Your physical therapist may also use massage techniques to reduce swelling and stiffness.
If your knee isn’t responding to the treatments above, your doctor may recommend arthroscopic surgery. Your doctor will give you specific instructions as to how to prepare for this surgery. Some example instructions may include:
- be fitted for crutches before your procedure and learn how to use them
- complete presurgery requirements, such as blood tests, X-rays, MRI, electrocardiogram (EKG), and other medical clearances, including an anesthesia clearance
- fill your prescription for pain medication before your procedure
- refrain from eating or drinking anything the night before your procedure
Notify your doctor if you experience any conditions that could keep you from having your surgery. These include:
- a fever
- an infection
- a cold
- an open wound
The surgeon will make a small incision in your knee. Your surgeon will insert tools and a camera through the incision to repair or trim away the damaged meniscus. The entire procedure typically lasts about an hour.
You can usually go home the same day after this procedure. Full recovery will take time. However, you can begin participating in physical therapy exercises within days after surgery.
If your procedure involves a meniscal repair, the recovery and rehabilitation time is about six weeks. You’ll wear a knee brace or crutches during this time.
Surgery involves risks and you should talk with your doctor to determine if you’re a good candidate for this procedure. The recovery period will include regular visits to the doctor as well as physical therapy to strengthen the muscles supporting your knee.
You can prevent meniscus tears by regularly performing exercises that strengthen your leg muscles. This will help stabilize your knee joint to protect it from injury.
You can also use protective gear during sports or a brace to support your knee during activities that may increase your risk of injury.
Always use proper form when exercising or engaging in activities that may put pressure on your knee joint. It’s a good idea to:
- warm up and stretch before exercising
- use proper gear, such as athletic shoes designed specifically for your activity
- lace up your footwear properly
- learn the proper techniques for the activities you engage in
With proper diagnosis and adherence to treatment, your knee can have the mobility and function it had before the injury. If a meniscus tear isn’t surgically treated, the potential for healing depends on the location of the tear.
Cartilage doesn’t have a significant blood supply, which can affect its ability to heal. However, there are some areas of the meniscus, such as the outer portions, which have more blood vessels and are more likely to heal.