As life happens, so do injuries, especially those that occur when we least expect them. Sometimes these injuries need special care and attention.  A torn meniscus in the knee, for example, whether the result of a quick pivot during a basketball game, an unexpected fall or just wear and tear over time, can have long-lasting effects. Like a lot of knee injuries, a meniscus tear can be painful and debilitating. Living without a meniscus can increase the risk of osteoarthritis and chronic knee pain. A meniscal transplant may be the answer. The best way to find out is to question the skilled and experienced orthopedic specialists at OCC – Advanced Orthopedic & Sports Medicine Specialists in Denver, Parker, or Aurora, Colorado. A meniscal transplant can allow young, active people to return to daily activities and can even help injured athletes return to their sport.

OVERVIEW

Meniscus tears are among the most common knee injuries affecting approximately 1 million people in the U.S. each year. They are one of the most frequently occurring cartilage injuries of the knee. When people talk about “torn cartilage” in the knee, they are usually referring to a torn meniscus. However, meniscal transplant surgery is rare and not for everyone. In a meniscus transplantation, a surgeon implants a new meniscus (taken from a cadaver) into the patient’s knee joint. This procedure is technically known as meniscal allograft transplantation (MAT). Allograft is a term that simply means “the transplantation of tissue from one person (a donor) to another”.

ABOUT THE MENISCUS

Three bones meet to form your knee joint: your thighbone (femur), shinbone (tibia), and kneecap (patella). A meniscus is a C-shaped wedge of rubbery cartilage that sits in the knee joint between the ends of the tibia (shinbone) and femur (thighbone). It is considered the knee’s main shock absorber. Each knee contains a medial (inner) and lateral (outer) meniscus, which together are called menisci (the plural of meniscus). The medial meniscus, on the inside of the knee, absorbs about 50% of impact to the knee joint – thus, it helps to prevent osteoarthritis, especially in somebody who is bowlegged (varus alignment). The role of the medial meniscus is also important in patients who are missing an anterior cruciate ligament (ACL) or who have previously received an ACL reconstruction.  The posterior horn of the medial meniscus serves as a backup to the anterior sliding of the knee, which can cause an ACL reconstruction to fail if the meniscus is not present to act as a bumper. The lateral meniscus absorbs more shock than the medial meniscus.  The lateral meniscus has been noted to absorb about 70% of the impact on the lateral compartment in the knee.  In addition to shock absorption, the lateral meniscus also plays a key role in the protection of an ACL reconstruction and provides stability in the presence of a torn ACL.  In the absence of an ACL and lateral meniscus – there is a significant amount of rotational instability.

WHAT IS A MENISCAL TRANSPLANT?

A meniscal transplant is a surgery to replace a damaged, torn, or missing meniscus. Surgeons usually perform this procedure on people under age 40 or 50 who are physically active and maintain a healthy weight. To be eligible for a meniscal transplant, there must be a missing part of the meniscus or it has a severe tear. Other parts of the knee should not have damage. If there is already arthritis present, and the cartilage in the knee has worn away too much, the procedure might not be successful. This is why for many older patients with this condition, a total or partial joint replacement might be the right option. Allograft tissue for a meniscal transplant (meniscal allograft transplantation – MAT) comes from a human donor, in this case, a cadaver (deceased donor). For allograft preparation, healthy cartilage tissue is taken from the cadaver and frozen. A screening process is done before selecting a possible donor. Someone who knows the donor well is interviewed to help identify risk factors that would prevent the use of the donor tissue. Once selected, the donor tissue undergoes many tests. The safety of the tissue is monitored by the American Association of Tissue Banks and the United States Food and Drug Administration. The tissue is tested for viruses like those that cause HIV/AIDS, West Nile virus, hepatitis B and C, as well as for bacteria. A meniscal transplant is not like a heart or lung transplant, in which “rejection” can occur. Additionally, patients do not need to be on immunosuppressants or other medications after the procedure.

CAUSES

A torn meniscus can result from any activity that causes forceful twisting or rotation of the knee. It’s a common sports injury in contact sports like football and wrestling, as well as in contact sports requiring jumping, sudden stops or turns, or pivoting, such as volleyball and soccer. Even kneeling, deep squatting, or lifting something heavy can sometimes lead to a torn meniscus. As one gets older, the cartilage in the knees wears down and gets weaker. This thinner cartilage can tear more easily. Arthritis (a breakdown of cartilage in the joints) can also lead to a meniscus tear.

SYMPTOMS

With a large tear, swelling will come right away, there will be a lot of pain and it will be hard to walk or straighten the knee. Sometimes, with a smaller tear, it might take 24 hours or more for pain and swelling to begin. Symptoms of a meniscus tear may be different for each person, but some of the most common are:

• Pain in the knee joint: usually on the inside (medial), outside (lateral) or back of the knee
• A popping sensation
• Stiffness
• Difficulty straightening the knee fully
• Catching or locking of the knee joint
• A feeling of the knee giving way

NON-SURGICAL TREATMENT

• Follow the RICE protocol: rest, ice, compression, elevation
• Pain medication — over-the-counter non-steroidal, anti-inflammatory drugs like NSAIDs (ibuprofen and naproxen)
• Corticosteroid injections
• Physical therapy

WHEN IS SURGERY INDICATED?

When conservative treatments have not brought relief, a meniscal transplant may be an option. A surgeon may recommend this procedure if the meniscus is severely damaged or if the meniscus was removed (meniscectomy) after a previous injury causing ongoing pain, swelling, or instability. It may be recommended for knee problems such as the development of early arthritis, inability to play sports, and knees that often give way or are unstable. To consider surgery, a patient should feel arthritis pain that measurably impacts everyday activities, causing them to stay in the house more or avoid activity altogether. Surgery may be an option if pain makes someone unable to go up and down stairs, makes a cane necessary, or causes trouble sleeping at night.             

GETTING THE RIGHT DIAGNOSIS. GETTING THE RIGHT DOCTOR.

There are many things to consider in getting meniscal transplant surgery. A torn meniscus can often be identified during a physical exam. Your doctor might move your knee and leg into different positions, watch you walk, and ask you to squat to help pinpoint the cause of your signs and symptoms. Two tests often used are the Thessaly and McMurray tests. Both allow your doctor to feel and listen for symptoms of a torn meniscus. X-rays may be ordered to rule out other problems with similar symptoms. An MRI  is the best imaging study to detect a torn meniscus. But surgeons also need to consider the pattern or shape of a tear to determine the best treatment approach. They also need to consider how good the blood supply is to the area of the meniscus tear as blood brings oxygen and other vital nutrients to tissues, enabling them to heal. The surgery is usually done with a knee arthroscopy. The surgeon makes several small incisions around the knee joint and inserts a narrow fiber optic scope (called an arthroscope) to examine the condition of the knee. Tiny instruments are used to remove any fragments of original meniscus cartilage. The new meniscal tissue is anchored into the shinbone to stabilize the transplant and then sewn into place. All of this takes extensive training, skill, and experience. You won’t find orthopedic surgeons more experienced or highly respected than those at Advanced Orthopedics in Denver, Parker, or Aurora, Colorado. Getting the best surgeon doesn’t just give you the best outcome, it gives you the best overall peace of mind.