The meniscus is a C-shaped spacer between the femur and the tibia and is located on the inside (medial) and outside (lateral) of the knee joint. It acts as a shock absorber and allows for smooth motion of the knee.

The meniscus is a commonly injured structure in the knee. This injury can occur in any age group. The meniscus is usually a tough structure in younger people and tears usually occur as a result of a forceful twisting injury. The meniscus becomes weaker with age, and a tear may occur as a result of a minor injury such as squatting.

The most common symptom of a torn meniscus is pain. The pain is usually felt along the joint line where the meniscus is located. If the torn portion of the meniscus is large enough, locking of the knee joint may occur. A meniscal tear will also cause irritation in the joint, which could result in knee swelling.

The diagnosis of a torn meniscus begins with an adequate history, which may include knee swelling, locking, and pain. Next, the physical examination will try to determine where the pain is located. The pain is usually located across the joint line. Sometimes a meniscal tear will produce clicks or a pop as the knee is moved through a range of motion. Plain x-rays will not show a torn meniscus, but they are useful to determine other conditions that may be present. An MRI scan (magnetic resonance imaging) may be obtained to confirm a meniscal tear. If the history and physical examination strongly suggests a torn meniscus, then arthroscopy may be suggested to confirm the diagnosis as well as treat the problem.

Only a small percentage of meniscal tears may heal by themselves. Thus, the initial treatment is directed towards reducing the pain and swelling in the knee. If the symptoms continue, arthroscopic surgery is recommended to either remove the torn portion of the meniscus or repair the meniscus. Arthroscopy involves inserting a small telescope into the knee joint through an incision. This allows the surgeon to identify the tear location and the type of tear. These factors help to determine if a tear can be repaired or if a tear should be removed.

Post-operatively the knee will be bandaged with an Ace wrap. If a repair was performed, a brace may be required. Crutches may also be used post-operatively. The patient will return for a follow-up visit in a few days for suture removal and an exercise program is also initiated at this time. The post-operative rehabilitation process varies with the seriousness of the injury and whether the meniscus was repaired or removed. The patient may return to work within several days, but if their job requires heavy lifting or climbing, the return may be delayed several weeks. The return to sporting activities varies, but on average, it is three weeks to three months for partial meniscal removal and approximately six months with a meniscal repair.