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 person who has died (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 people still 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 done 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 tissue taken from a cadaver (allograft).

If your doctor finds 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 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. You will likely be 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 check the cartilage and ligaments of your knee. Then the surgeon will confirm that a meniscus transplant is appropriate, and that you don't have severe arthritis of the knee.

The new meniscus will be prepared to fit your knee correctly. If any tissue remains 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. Another incision may be needed to sew the meniscus in place. Screws or other devices may be used to hold the meniscus in place.

At the surgery is finished, 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
• Unstable knee
• Knee that gives 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 very successful. Most people have less knee pain after meniscal allograft transplantation.

After the surgery, you will probably wear a knee brace for the first 1 to 6 weeks. You also may need crutches for 1 to 6 weeks. Most people can 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. Therapy lasts for between 2 and 6 months.

How soon you can return to work will depend on your job, but it can take anywhere from a few weeks to a few months. Most people have to wait between 6 months and 1 year to fully return to activities and sports.