What is a meniscus tear?
The meniscus is a C-shaped piece of cartilage in the knees. There are two in each knee: The medial meniscus is on the inside of the knee, and the lateral is on the outside. The menisci are attached to the tibia (shinbone) and act as shock absorbers that help cushion and stabilize the knee joint.
Meniscus tears are some of the most common sports injuries. There are a number of different types that are classified by how they look and where the tear is located on the meniscus. Common types of tears include:
- Bucket handle tear—This type of tear occurs when a piece of cartilage partially detaches and flips open, the way a bucket handle can move 180 degrees. It can often snag on other portions of the knee anatomy, which can cause a sensation of the knee catching, locking or feeling unstable.
- Degenerative tear—This tear is a fraying of the edge of the meniscus.
- Flap tear—This tear looks similar to a bucket handle tear, except the torn tissue is on the surface of the meniscus and does not go all the way through the cartilage.
- Radial tear—This type of tear occurs near the outside of the meniscus.
Causes and Risk Factors
In athletes, a meniscus tear can be a sudden, acute injury. In addition, squatting and twisting motions—in both exercise and sports—often cause acute meniscus tear injuries, as well.
Degenerative tears are more common in older people and can occur with little or no force or trauma.
Symptoms of a meniscus tear can include:
- A feeling of instability in the knee
- A popping sound following an injury
- Catching or locking of the knee
- Reduction in range of motion
- Stiffness or swelling
A diagnosis of a meniscus tear usually starts with a medical history and physical examination. Doctors will be looking for evidence of an acute injury and listening for the patient’s description of symptoms, and will likely manipulate the knee in various directions. The diagnosis is typically confirmed using the history and exam alone.
In certain situations, imaging studies may be useful in confirming a diagnosis. A torn meniscus will not show up on an X-ray because the meniscus is made of soft tissue. However, an X-ray can help identify or rule out other sources of pain, such as a fracture. Magnetic resonance imaging (MRI)—which uses radio waves and magnetic fields to scan and return images of soft tissue—can detect a meniscus tear.
Meniscus tears can sometimes be treated without surgery, depending on the severity and location of the injury. In such cases, anti-inflammatory medication, physical therapy and the RICE protocol—rest, ice, compression, elevation—may be used.
However, much of the meniscus does not have a blood supply; therefore, tears in those regions cannot repair themselves. In that case, surgery will be necessary.
Meniscus surgery is usually done arthroscopically, with small tools and incisions and a flexible camera called an arthroscope attached to a video monitor. Surgeons will use one of two techniques: meniscus repair or partial meniscectomy. In a meniscus repair, they will stitch the tear back together. In a partial meniscectomy, surgeons will remove the torn pieces of the meniscus.
A meniscectomy generally has a shorter recovery time than a repair: one to two months as opposed to three to five. A brace may be necessary after the surgery to immobilize the knee and promote healing, and the patient will use crutches initially to keep weight off the knee. The surgical team may recommend physical therapy to return range of motion and strength to the injured leg.
If you suspect you’ve torn your meniscus, schedule an appointment with one of our orthopedic surgeons today to discuss your treatment options.