What is a torn meniscus?

A tear of, or rent in, the cartilage in the knee is called a torn meniscus. Tears are described by how they look and where they are located. This information is usually found during a diagnostic procedure, like an MRI or knee arthroscopy.

What causes a meniscus to tear?

A forceful twist or sudden stop can cause the femoral condyle to grind into the tibial plateau and pinch and sometimes tear the meniscus. This can also occur with a deep squatting or kneeling, especially when lifting a heavy weight. Torn meniscus injuries often occur after athletic activities, especially in contact sports like football and hockey or those where pivoting and sudden stops occur like tennis and basketball.

The risk of developing a torn meniscus increases with age as the cartilage begins to wear and lose its resilience. Increasing weight also puts more stress on the meniscus with the potential for wear, degeneration, and tearing.

Because of the forces applied to the knee, a torn medial meniscus may also be associated with tears of the medical collateral ligament and anterior cruciate ligament within the knee joint.

What are symptoms and signs of a torn meniscus?

When a meniscus is torn, there may be an acute onset of pain in the knee and it may cause a "pop" sensation. Over a period of a few hours, swelling may occur within the knee, but this may not necessarily be noticed. Sometimes, though, the patient may not be aware that an injury occurred.

After the injury, the knee joint may gradually settle down and feel relatively normal. However, other symptoms may develop, such as:

•  pain with running or walking longer distances

•  intermittent swelling of the knee joint. Many times, the patient may feel that the knee feels "tight"

• popping, especially when climbing up or down stairs

• giving way (the sensation that the knee is unstable and a sense that the knee will give way); or

• locking (a mechanical block where the knee cannot be fully extended or straightened). This occurs when a piece of torn meniscus folds on itself and blocks full range of motion.

What is the treatment for a torn meniscus?

The treatment of a torn meniscus depends on its severity, location, and underlying disease within the knee joint.

Torn meniscus due to injury

Initial therapy after the injury includes rest, ice, compression, and elevation (RICE). This may be helpful in alleviating the inflammation within the joint that occurs with a torn meniscus. Anti-inflammatory medications may help to relieve pain and inflammation.

Many patients choose initial conservative or nonsurgical treatment of a torn meniscus. Once the initial injury symptoms have settled down, exercise programs may be recommended to strengthen the muscles surrounding the knee to add to the stability of the joint. Maintaining an ideal body weight will also help lessen the forces that can stress the knee joint. Orthotics may be useful to distribute the forces generated by walking and running.

If conservative therapy fails, surgery may be a consideration. Knee arthroscopy allows the orthopedic surgeon to assess the tear within the meniscus and repair it. Options include sewing the torn edges together or trimming the torn area and smoothing the injury site.

Degenerative joint disease

In older patients with degenerative joint disease (also known as osteoarthritis),where the cartilage wears out.

Exercise and muscle strengthening may be an option to protect the joint and maintain range of motion. As well, anti-inflammatory medications may be considered to decrease swelling and pain arising from the knee joint.

Steroid injections into the knee joint may be a consideration to bring temporary symptom relief that can last weeks or months.

Joint replacement may be an option with substantial degeneration of the knee if conservative measures fail and symptoms of pain and decreasing joint range of motion progress.

Treatment of a torn meniscus may include surgery to repair the damage. Some meniscal tears can be watched and treated with physical therapy (physiotherapy) and muscle strengthening to stabilize the knee joint.