Meniscus tears are the most common knee injuries. Tears can occur from twisting or pivoting injuries and are common in cutting or contact sports. However they can also occur without a specific injury in older patients where the menisci start to wear out with age and become more stiff, less forgiving, and consequently more fragile.
The knee joint is made up of three bones: the thighbone (femur), shinbone (tibia), and kneecap (patella). Two C-shaped pieces of cartilage act as "shock absorbers" between your femur and tibia. They are called the medial and lateral meniscus. The lateral meniscus is on the outside half of the knee and medial meniscus is on the inner half of the knee. They are tough and rubbery to help cushion the joint and keep it stable and transfer the load from the femur to the tibia.
There are different types of meniscus tears. They are described by where they are located in the meniscus and the appearance of the tear. Some types of tears include horizontal, longitudinal/vertical, radial, parrot peak, flap tears or complex tears. When tears occur from an athletic injury, they can also be associated with other injuries of the knee including ACL and MCL tears.
Acute meniscal tears can happen during sports. Twisting the knee when it is bent can cause a tear. Contact such as tackles in football also can cause tears. Planting, pivoting and cutting movements are other common mechanisms.
Older patients can develop tears without specific injuries. The menisci, like other tissues in the body, wears out with age and can be more prone to tear. Movements that are common in daily activities such as getting out of a car or chair or kneeling or squatting down can cause a tear.
Often times, patients don’t recall an injury and just develop symptoms over the course of a few days. These types of tears can be associated with arthritis.
Sometimes a "pop" or "click" is heard when a meniscus is torn. Other times, nothing is felt at the time of the injury and over the course of hours or days, the knee becomes swollen, stiff and sore. Sometimes there is catching, clicking or locking or the knee may feel like it will "give way." Often times some range of motion of the knee is lost.
If you have had an injury to the knee and have some of the above symptoms, it is advisable to have your knee evaluated by an orthopedic doctor. After asking you about the symptoms and your medical history, the doctor will examine your knee. After looking at the knee and checking range of motion, the space between the bones will be palpated. Tenderness there can indicate a meniscus tear. A test called McMurray’s involves bending, straightening and rotating the knee to see if this causes pain or popping. The ligaments will also be evaluated to determine if the knee is stable.
In addition to examining the knee, your doctor may order tests for further evaluation.
Although x‑rays do not show meniscal tears, they may show other causes of knee pain, such as osteoarthritis and are the first step in imaging the knee.
Magnetic resonance imaging (MRI)
This test shows both the bones and all the soft tissues, including the meniscus, cartilage and ligaments. A tear in the meniscus can usually be seen on an MRI, as well as other potential injuries.
How your orthopedic surgeon treats your tear will depend on the type of tear you have, its size, and location, along with other problems that you might have with the knee. In general, the blood supply to the meniscus is limited and therefore the body has a limited ability to heal meniscus tears.
The outside one‑third of the meniscus has a good blood supply. A tear in this "red" zone can sometimes be repaired with surgery. A longitudinal or vertical tear is an example of this kind of tear.
In contrast, the inner two‑thirds of the meniscus has no blood supply and even if repaired. Tears in this "white" zone cannot heal. Because the pieces can’t heal back together, tears in this location are usually surgically trimmed away, called partial meniscectomy or debridement. Along with the type of tear you have, your age, activity level, and any related injuries will factor into your treatment plan.
Not all tears require surgery. If the tear is small and does not cause mechanical symptoms, sometimes the symptoms improve with time and the knee returns to feeling normal. However, meniscal tears cannot actually heal themselves. Nonoperative treatment is best for very small tears without moving parts.
After pain develops, the first treatment is the RICE protocol:
Rest. Decrease activity level, stay off the knee and allow it to recover. Sometimes this involves using crutches for a short period of time.
Ice. Use ice or cold packs 20 minutes at a tie multiple times a day. Do not apply ice directly to the skin.
Compression. Wearing an ACE bandage or sleeve can help decrease swelling and pain.
Elevation. Elevate the leg above the level of the heart to reduce swelling.
Non‑steroidal anti‑inflammatory medicines. Drugs like Aleve (Naprosyn) and Advil or Motrin (Ibuprofen) can reduce pain and swelling.
If your symptoms persist with nonsurgical treatment, your doctor may suggest arthroscopic surgery. This involves making small incisions and placing a camera and very small instruments into the joint to perform various procedures in a minimally invasive technique.
In this procedure, the damaged meniscal tissue is trimmed away to make the remaining meniscus smooth and stable. The goal is to keep as much of the normal meniscus as possible.
Some meniscal tears can be repaired by suturing (stitching) the torn pieces together. Whether a tear can be successfully treated with repair depends upon the type of tear, as well as the overall condition of the injured meniscus. Because the meniscus must heal back together, recovery time for a repair is much longer than from a meniscectomy and may involve the use of a brace to protect the repair.
To help recover from the surgery, your doctor my recommend physical therapy and exercises at home to help regain your range of motion and strength and to help you return to your normal activities. Recovery for a meniscus repair is about 3‑4 months. A meniscectomy requires less time for healing and many people can return to their normal activities within 3‑4 weeks.