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.

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 new meniscus can help knee pain and possibly prevent future arthritis. The new meniscus is an allograft, a tissue taken from a cadaver.

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 usually performed by knee arthroscopy. 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 may be required to sew the meniscus in place. Screws or other devices may be 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.

Meniscus allograft transplantation may be recommended for knee problems such as:

• Knee pain
• Instability
• Giving way
• Inability to play sports or other activities

The risks for any anesthesia are:

• Allergic reactions to medications
• Problems breathing

The risks for any surgery are:

• Bleeding
• Infection
• Nerve damage

Additional risks include:

• Stiffness of the knee
• Failure of the surgery to relieve symptoms
• Failure of the meniscus to heal
• Tear of the new meniscus
• Disease transmission from the cadaver's meniscus
• Pain in the knee
• Weakness of the knee

Meniscus allograft transplantation is difficult surgery. However, in people who are missing the meniscus and have pain, it can be a very successful procedure. A decrease in knee pain can be expected in up to 80% of patients after meniscal allograft transplantation.

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 immediately after surgery to help prevent any stiffness. Pain is usually managed with medications.

Physical therapy may help you regain the motion and strength of your knee. The length of therapy can vary, but can last from two to six months.

Activities such as returning to work will depend on your occupation, but can be anywhere from a few weeks to a few months. A full return to activities and sports generally takes from six months to one year.