The meniscus is a piece of cartilage found in the knee joint that serves as a buffer and shock-absorption system for the bones in the knee. Sometimes, the meniscus can tear, resulting in the need for surgical repair. Learn more about meniscus tears and ways they can be repaired by clicking on the questions below.

What is the meniscus?

The meniscus is a C-shaped fibrous piece of cartilage found in the knee joint which/that forms a buffer between the bones to protect the joint. The meniscus also serves as a shock-absorption system, assists in lubricating the joint, limits the joint flexion and extension, and distributes body weight across the knee joint.


What is a meniscus tear?

A meniscal tear, a common knee joint injury, is an injury of the shock-absorbing cartilage in the knee.


What causes a meniscus tear?

Meniscal tears are most commonly caused by twisting or hyperflexion (pivoting motion) of the joint. This can happen during certain activities, such as when lifting or playing tennis. Meniscus tears can also occur due to degenerative processes ”” as we age, the meniscus becomes worn and can tear more easily.


What are the symptoms of a meniscus tear?

Pain and swelling may be the primary symptoms. Joint locking is another common complaint. The most common symptoms of a meniscus tear are:

  • Knee pain, often perceived as being located in the space between the bones, and which gets worse when gentle pressure is applied to the joint ( palpation )

  • A "pop" noted at the time of injury

  • Joint tenderness may be noted

  • Recurrent knee-catching

  • Locking of the joint.


How is the diagnosis of a meniscus tear made?

A physical examination shows signs of torn meniscus. This includes various manipulations of the joint.

  • Pain on the joint line in the area of the meniscus tear.

  • In the McMurray's test, you will have you lie on your back while pressure is placed on the outside of the knee by the doctor. The leg is rotated and pain and/or a click within the joint indicate a meniscal tear.

  • A ballottement test for synovial effusions (excess joint fluid) is often positive in meniscal tears, indicating swelling with fluid around the joint. This test is a physical examination test that allows the doctor to detect the presence of fluid in a body space.

Other tests that show meniscus tears may include:

  • A knee MRI

  • A weight bearing knee joint X-ray.


What are some common treatments?

Many tears can be treated non-operatively. The goal of treatment is to minimize the symptoms and protect the joint from further injury while it heals.

A knee immobilizer is often applied to prevent further injury to the joint. Ice is applied to reduce swelling, and nonsteroidal anti-inflammatory drugs (NSAIDS) and cortisone injections may be given to reduce swelling and pain.

Physical therapy should be involved to help regain joint and leg strength.

If the injury is acute, and/or you have a high activity level, knee arthroscopy (surgery) may be necessary. Age has an effect on treatment. Younger patients are more likely to have problems without surgery.


What is a meniscus transplant?

Meniscus transplant, also known as, Meniscal allograft transplantation, is a type of surgery in which a new meniscus, a cartilage ring in the knee, is placed into your knee. The new meniscus is taken from a cadaver donor. This has become a treatment option for people with specific types of knee pain.

There are two cartilage rings in the center of each knee, one on the inside (medial meniscus) and one on the outside (lateral meniscus). When a meniscus is torn, it is commonly removed by knee arthroscopy . However, some patients continue to have pain after the meniscus is removed, or several years after the meniscus is removed.

A meniscus transplant places a new meniscus in your knee where the meniscus is missing. This procedure is only performed in cases of meniscus tears that are so severe that all or nearly all of the meniscus cartilage has to be removed. The new meniscus can help knee pain and possibly prevent future arthritis. The new meniscus is an allograft, a tissue taken from a cadaver.


How is the transplant done?

If your doctor determines that you are a good candidate for a meniscus transplant, X-rays of your knee are usually taken to find a meniscus that will fit correctly into your knee. The allograft is tested in the lab for possible diseases.

Other surgeries, such as ligament or cartilage repairs, may be performed at the time of the meniscus transplantation or with a separate surgery.

The meniscus transplant is done with arthroscopic assistance as well as open incision. Most patients are asleep during the surgery. When arthroscopy is performed, a camera is inserted into your knee through a small poke hole, and is connected to a video monitor. First, the surgeon will evaluate the cartilage and ligaments of your knee. Then the surgeon will confirm that a meniscus transplant is appropriate, and that there is no severe arthritis of the knee.

The new meniscus will be prepared to fit your knee correctly. If there is any tissue remaining from your old meniscus, it will be removed using a shaver or other instruments. A small incision is made in the front of your knee to insert the new meniscus into the knee. Sutures are used to sew the new meniscus in place. An additional incision is required to sew the meniscus in place. Stitches are used to hold the meniscus in place.

At the completion of the surgery, the incisions are closed, and a dressing is applied. During the arthroscopy, most surgeons take pictures of the procedure from the video monitor to show you what was found and what was done.


Who is a good candidate?

  • Younger to middle age patients (less than 50 years old)

  • Patient who has already undergone a prior meniscectomy (meniscus removal surgery)

  • Patient has normal or limited damage to the articular cartilage of the joint.

This procedure is only for patients who have already had most of the meniscus removed. Patients who have this accelerated degenerative change to their knee joint are not good candidates for meniscus transplant surgery.


Who should not have this procedure done?

  • Patients who still have a significant portion of the meniscus

  • Patients who have degenerative changes within the joint (early arthritis)

  • Patients who have instability or malalignment of the knee joint


What can I expect after the surgery? How long will recovery take?

Following the surgery, many patients are placed into a knee brace for the first one to six weeks. Crutches are also necessary for one to six weeks. Most patients are allowed to move the knee within a few weeks after surgery to help prevent any stiffness. Pain is usually managed with medications.

Physical therapy will help you regain the motion and strength of your knee. Therapy lasts between three and six months.

When you can return to work will depend on your occupation, but can take anywhere from a few weeks to a few months. A full return to activities and sports generally takes from six months to one year.


Why chooses University of Maryland Orthopaedics?

The University of Maryland Orthopaedics Knee Program provides a multidisciplinary approach to the treatment of a variety of knee conditions. Our team uses the latest advances in knee diagnosis, treatment and rehabilitation to increase patients' mobility, diminish pain, increase function and improve quality of life. Our surgeons have a great deal of experience with meniscus tear transplants and other orthopedic procedures of the knee. They use the most advanced contemporary approaches -- including minimally invasive techniques -- to provide the highest quality of care.


Patient Success Story

Read about UMMC patient Casey Whelan who had a cartilage transplant and how her life has changed since having the procedure.


To make an appointment with one of our orthopedic specialists or to learn more about our services, centers and treatment options, please call 410-448-6400.