Meniscus tears are among the most common knee injuries. A torn meniscus is a tear in the cartilage of the knee. Athletes, particularly those who play contact sports, are at risk for meniscus tears.
A meniscus tear is often caused by a single acute injury—such as a sudden twist or quick turn during sports activity. Because the menisci weaken and wear thin over time, older people are more likely to experience a degenerative meniscus tear. So, anyone at any age can tear the meniscus. When people talk about “torn cartilage” in the knee, they are usually referring to a torn meniscus.
The meniscus functions to improve the fit between the femur and the tibia, to absorb shock and distribute load in the knee, and to help move lubricating fluid around the knee. The meniscus can tear from either trauma or injury or from degeneration.
The meniscus is a rubbery, C-shaped disk that acts as a “shock absorber” between the thighbone and shinbone. It helps cushion and stabilize the knee joint. Each knee has two menisci—one on the outside of the knee and one on the inside.
In many cases, a surgical procedure called “arthroscopy” is used to repair or remove a torn meniscus.
Normal knee anatomy. The menisci are two rubbery disks that help cushion the knee joint.
The meniscus can tear from acute trauma or as the result of degenerative changes that happen over time. Tears are noted by how they look, as well as where the tear occurs in the meniscus. Common tears include bucket handle, flap, and radial.
Sports-related meniscus injuries often occur along with other knee injuries, such as anterior cruciate ligament (ACL) tears.
Types of meniscus tears:
(Left) Bucket handle tear. (Right) Flap tear.
(Left) Radial tear. (Right) Degenerative tear.
Acute meniscus tears often happen during sports. These can occur through either a contact or non-contact injury—for example, a pivoting or cutting injury.
As people age, they are more likely to have degenerative meniscus tears. Aged, worn tissue is more prone to tears. An awkward twist when getting up from a chair may be enough to cause a tear in an aging meniscus.
You might feel a “pop” when you tear the meniscus. Most people can still walk on their injured knee and many athletes are able to keep playing with a tear. Over 2 to 3 days, however, the knee will gradually become more stiff and swollen.
The most common symptoms of a meniscus tear are:
- Stiffness and swelling
- Catching or locking of your knee
- The sensation of your knee “giving way”
- Inability to move your knee through its full range of motion
Because other knee injuries can cause similar symptoms, your doctor may order imaging tests to help confirm the diagnosis.
MRI scans show (left) a normal meniscus and (right) a torn meniscus. The tear can be seen as a white line through the dark body of the meniscus.
During the exam, your doctor will look for signs of tenderness along the joint line.
The treatment your doctor recommends will depend on a number of factors, including your age, symptoms, and activity level. He or she will also consider the type, size, and location of the injury.
Many meniscus tears will not need immediate surgery. If your symptoms do not persist and you have no locking or swelling of the knee, your doctor may recommend nonsurgical treatment.
If your symptoms persist with nonsurgical treatment, your doctor may suggest arthroscopic surgery.
Procedure. Knee arthroscopy is one of the most commonly performed surgical procedures. In this procedure, the surgeon inserts a miniature camera through a small incision (portal) in the knee. This provides a clear view of the inside of the knee. He or she then inserts surgical instruments through two or three other small portals to trim or repair the tear.
Illustration and photo show a camera and instruments inserted through portals in a knee.
Partial meniscectomy. In this procedure, the damaged meniscus tissue is trimmed away. This procedure typically allows for immediate weight bearing, and full range of motion soon after surgery.
Meniscus repair. Some meniscus tears can be repaired by suturing (stitching) the torn pieces together. Whether a tear can be successfully repaired 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 longer than for a meniscectomy.
Close-up of partial meniscectomy
A torn meniscus repaired with sutures
Once the initial healing is complete, your doctor will prescribe rehabilitation exercises. Regular exercise to restore your knee mobility and strength is necessary. You will start with exercises to improve your range of motion. Strengthening exercises will gradually be added to your rehabilitation plan.
In many cases, rehabilitation can be carried out at home, although your doctor may recommend working with a physical therapist. Rehabilitation time for a meniscus repair is about 3 to 6 months. A meniscectomy requires less time for healing — approximately 3 to 6 weeks.
Meniscus tears are extremely common knee injuries. With proper diagnosis, treatment, and rehabilitation, patients often return to their pre-injury abilities.
This information is provided as an educational service and is not intended to serve as medical advice. To get specific orthopaedic advice or assistance you need consult Dr Peter Smith or any orthopaedic surgeon.