The menisci are commonly referred to as the sports cartilages in the knee. There are 2 menisci, one on the outside and one on the inside. The are shaped like semicircular discs and act as shock absorbers and stabilisers within the knee. Meniscal tears may occur following traumatic twisting injuries to the knee. Sometimes they may be damaged with relatively minor trauma. Traumatic tears often give rise to very mechanical symptoms with sensations of the joint jamming or locking. A Knee arthroscopy may be suggested.

Degenerative tears often give more vague symptoms of stiffness, swelling and aching after activities. These symptoms may settle down with appropriate simple treatments including anti-inflammatory medication and appropriate physiotherapy.

Signs and symptoms

The most common problem caused by a torn meniscus is pain. The pain may be felt along the line of the joint where the meniscus lies or be more vague and felt all over the knee. It is often made worse with twisting, squatting or impact activites when the meniscus can be pinched. With rest the symptoms may settle. The joint may become swollen. If the torn part of meniscus is large locking may occur. This is caused by a large fragment getting caught in the hinge mechanism of the knee and acting like a wedge preventing the knee from fully straightening.

Treatment

Initial treatment for a torn meniscus is directed towards reducing the pain and swelling in the knee. This can be achieved by resting the knee, icepacks and anti-inflammatory medications. If the knee is locked and cannot be straightened out, surgery may be recommended as soon as reasonably possible to remove the torn portion that is caught in the knee joint. Once a meniscus is torn, it will most likely not heal on its own. Symptoms in a large number of patients with degenerative tears will settle with appropriate treatment (anti inflammatory medication and appropriate physiotherapy). The symptoms may recur intermittently but if they can be managed relatively easily then retaining the degenerate meniscus may be better for the knee in the long term. If the symptoms continue, surgery will be required to either remove the torn portion of the meniscus or to repair the tear.

Surgery

Meniscal surgery is done using an arthroscope (Keyhole surgery). Small incisions are made in the knee to allow the insertion of a small TV camera into the joint. Through another small incision, special instruments are used to remove the torn portion of meniscus while the arthroscope is used to see what is happening. In some cases the meniscus tear can be repaired. Sutures are then placed into the torn meniscus until the tear is repaired. Repair of the meniscus is not possible in all cases. Young people with relatively recent meniscal tears are the most likely candidates for repair. Degenerative type tears in older people are not usually repairable.