What is a torn meniscus?

There are three bones in the knee. These are the femur, tibia, and patella. The ends of those bones are covered with cartilage. This is a smooth material that cushions the bone and allows the joint to move easily without pain. The cartilage acts as a shock absorber. Between the bones of the knees are two crescent-shaped disks of connective tissue, called menisci. These also act as shock absorbers to cushion the lower part of the leg from the weight of the rest of the body.

Front view of knee joint.

What causes a torn meniscus?

Meniscus tears can happen during a sudden rotating movement while bearing weight, such as when twisting the upper leg while the foot stays in one place during sports and other activities. This is known as a traumatic tear. Or meniscal tears can develop over time (degenerative). This is when routine activities, such as jogging or yard work, cause tears in the meniscus that have been weakened over time because of age, arthritis, or other conditions. Degenerative meniscal tears are most common in adults older than 40. Tears can be minor, with the meniscus staying connected to the knee. Or they can be major, with the meniscus barely attached to the knee by a cartilage thread.

What are the symptoms of a torn meniscus?

Each person may have different symptoms. But the most common symptoms are:

  • Pain, especially when holding the knee straight
  • Swelling and stiffness
  • Knee may catch, click, or lock
  • Knee may feel weak or unstable
  • Less range of motion

These symptoms may look like other health conditions or problems. Always talk with your healthcare provider for a diagnosis.

How is a torn meniscus diagnosed?

Your healthcare provider will ask about your medical history and do a physical exam. You may also need:

  • X-ray. This test uses invisible electromagnetic energy beams to make images of internal tissues, bones, and organs onto film.
  • MRI. This test uses a combination of large magnets, radio waves, and a computer to make detailed images of organs and structures within the body. It can often find damage or disease in a surrounding ligament, tendon, bone, or muscle.
  • Arthroscopy. This is a minimally invasive surgical procedure used for conditions of a joint. It uses a small, lighted, optic tube (arthroscope). The tube is inserted into the joint through a small incision in the joint. Images of the inside of the joint are projected onto a screen. They are used to evaluate any degenerative or arthritic changes in the joint. The procedure also may find bone diseases and tumors, as well as determine the cause of bone pain and inflammation.

How is a torn meniscus treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how bad the condition is.

Treatment may include:

  • Resting, icing, and elevating your knee
  • Compression bandage
  • Medicine to relieve pain and reduce inflammation, such as ibuprofen
  • Muscle-strengthening exercises
  • Physical therapy
  • Arthroscopic surgery

What are possible complications of a torn meniscus?

An untreated torn meniscus can result in instability of the knee and lasting pain. It can also increase your risk of osteoarthritis.

When should I call my healthcare provider?

Call your healthcare provider if your knee:

  • Locks or catches or makes a clicking, popping, or grinding sound
  • Is painful and swollen
  • Feels weak or buckles

Key points about a torn meniscus

  • Torn meniscus is often caused by a twisting movement of the knee while bearing weight. Or it can develop over time from routine activities.
  • A torn meniscus causes pain, locking, or clicking, and weakness of the knee.
  • Exercises, medicine, and arthroscopy may be used to treat a torn meniscus.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
  • Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are and when they should be reported.
  • Ask if your condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if you do not take the medicine or have the test or procedure.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your healthcare provider if you have questions, especially after office hours or on weekends and holidays.

Understanding Meniscal Transplant Surgery

Understanding Meniscal Transplant Surgery

Meniscal transplant surgery is done to replace a small piece of missing or damaged cartilage in the knee. It's replaced with one from a cadaver donor.

What is the meniscus?

Your knee has two wedge-shaped pieces of cartilage. They lie on each side of your knee. Each piece is called a meniscus. They act as shock absorbers between your thighbone (femur) and your shinbone (tibia). The rubbery menisci help protect the ends of your bones as they move together.

A twisting injury may badly damage your meniscus. It may need to be removed if the damage is bad enough. Without this cushion, the ends of your bones may start to rub together. This can cause knee pain and arthritis over time.

Front view of knee showing medial meniscus and lateral meniscus.

Why meniscal transplant surgery is done

Meniscal transplant surgery may be done if your meniscus was taken out in a past surgery. With no meniscus, you may get knee pain and arthritis of the knee. Replacing it may give you pain relief. It may also help prevent arthritis. This surgery is less invasive than knee replacement surgery. Meniscal transplant surgery may not be a choice if you already have arthritis of your knee.

Meniscal transplant surgery may be a choice if you:

  • Are age 45 or younger and physically active

  • Are missing a large part of your meniscus. Or if you have a large meniscus tear that can’t be repaired.

  • Have severe or ongoing knee pain with activity

  • Have no or only a small amount of arthritis

  • Have a knee with normal alignment and stable ligaments

  • Are not obese

How meniscal transplant surgery is done

Your surgery will be done by an orthopedic surgeon. This is a surgeon who specializes in treating bone, muscle, joint, and tendon problems.

The surgery can be done in several ways. The surgeon will make one or more small cuts (incisions) through the skin and muscle of your knee. They will put a very small camera through this cut. This is used to help guide the surgery. Any remaining meniscus is removed with very small tools put through the cut. The surgeon will stitch the donated meniscus into the joint. Screws or other devices may be used to hold it in place.

Risks of meniscal transplant surgery

All surgery has some risks. The risks of this surgery include:

  • Stiffness of the joint after surgery (more common)

  • Incomplete healing and need for another surgery

  • Too much bleeding

  • Infection

  • Damage to nearby nerves

  • Problems from anesthesia

  • An infection from the donated tissue (very rare)

Your own risks may be different based on your age, overall health, and other things. Ask your surgeon about the risks that most apply to you.