Meniscal allograft transplantation

If your surgeon finds that you are a good candidate for a meniscus transplant, x-rays or an MRI of your knee are usually taken to size your knee in order to find a meniscus that will fit your knee. The donated meniscus is tested in the lab for any diseases and infection.

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

You will likely receive general anesthesia before this surgery. This means you will be asleep and unable to feel pain. Or, you may have regional anesthesia. Your leg and knee area will be numbed so that you do not feel any pain. If you receive regional anesthesia, you will also be given medicine to make you very sleepy during the operation.

During the surgery:

• The meniscus transplant is usually performed using knee arthroscopy. The surgeon makes two or three small cuts around your knee. Salt water (saline) will be pumped into your knee to inflate the knee.
• The arthroscope is inserted into your knee through a small incision. The scope is connected to a video monitor in the operating room.
• The surgeon inspects the cartilage and ligaments of your knee, confirming that a meniscus transplant is appropriate and that you don't have severe arthritis of the knee.
• The new meniscus is prepared to fit your knee correctly.
• If any tissue is left from your old meniscus, it is removed.
• The new meniscus is inserted into your knee and sutured (sewn) in place. Screws or other devices may be used to hold the meniscus in place.

After the surgery is finished, the incisions are closed. A dressing is placed over the wound. During arthroscopy, most surgeons take pictures of the procedure from the video monitor to show you what was found and what was done.

Menisci are two cartilage rings that are in each knee. One is on the inner side of the knee (medial meniscus) and one is on the outer side (lateral meniscus). When a meniscus is torn, it is commonly removed by knee arthroscopy. Some people can continue to have pain after the meniscus is removed.

A meniscus transplant places a new meniscus in the knee where the meniscus is missing. This procedure is only done when meniscus tears are so severe that all or nearly all of the meniscus cartilage is torn or has to be removed. The new meniscus can help with knee pain and possibly prevent future arthritis.

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

• Development of early arthritis
• Inability to play sports or other activities
• Knee pain
• Knee that gives way
• Unstable knee
• Persistent knee swelling

Risks of anesthesia and surgery in general are:

• Allergic reactions to medicines
• Problems breathing
• Bleeding, blood clots, infection

Risks of meniscal transplant surgery are:

• Nerve damage
• Stiffness of the knee
• Failure of the surgery to relieve symptoms
• Failure of the meniscus to heal
• Tear of the new meniscus
• Disease from the transplanted meniscus
• Pain in the knee
• Weakness of the knee

Tell your health care provider what medicines you are taking. This includes medicines, supplements, or herbs you bought without a prescription.

During the 2 weeks before your surgery:

• You may be asked to temporarily stop taking blood thinners. These include aspirin, ibuprofen (Advil, Motrin), naproxen (Naprosyn, Aleve), and other medicines.
• Ask your surgeon which medicines you should still take on the day of your surgery.
• If you have diabetes, heart disease, or other medical conditions, your surgeon will ask you to see your provider who treats you for these conditions.
• Tell your provider if you have been drinking a lot of alcohol, more than 1 or 2 drinks a day.
• If you smoke, try to stop. Ask your provider for help. Smoking can slow wound and bone healing.
• Tell your surgeon if you develop a cold, flu, fever, herpes breakout, or other illness before your surgery. The procedure may need to be postponed.

On the day of surgery:

• Follow instructions on when to stop eating and drinking before the surgery.
• Take the medicines your provider told you to take with a small sip of water.
• Follow instructions on when to arrive at the hospital. Be sure to arrive on time.

Follow any discharge and self-care instructions you are given.

After the surgery, you will probably wear a knee brace for the first 6 weeks. You will need crutches for 6 weeks to prevent putting full weight on your knee. You will likely be able to move the knee right after surgery. Doing so helps prevent stiffness. Pain is usually managed with medicines.

Physical therapy can help you regain the motion and strength of your knee. Therapy lasts for between 4 and 6 months.

How soon you can return to work depends on your job. It can take from a few weeks to a few months. It can take 6 months to a year to fully return to activities and sports.

Meniscus allograft transplantation is a difficult surgery, and the recovery is hard. But for people who are missing the meniscus and have pain, it can be very successful. Most people have less knee pain after this procedure.

Meniscus transplant; Surgery - knee - meniscus transplant; Surgery - knee - cartilage; Arthroscopy - knee - meniscus transplant

Phillips BB, Mihalko MJ. Arthroscopy of the lower extremity. In: Azar FM, Beaty JH, eds. Campbell's Operative Orthopaedics. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 51.

Ruzbarsky JJ, Maak TG, Rodeo SA. Meniscal injuries. In: Miller MD, Thompson SR, eds. DeLee, Drez & Miller's Orthopaedic Sports Medicine: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2020:chap 94.

Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.