Meniscus Tears

Meniscus Tears/ web based movie

Overview

The knee joint is made up of three bones- t he thigh bone (femur), the shin bone (tibia), and the kneecap (patella). Two types of cartilage are present in the knee. The first is the “hard” cartilage, termed “articular cartilage” that covers the ends of the bones and helps with smooth joint motion. When the articular cartilage wears down with age this is called “osteoarthritis.” The knee joint also contains the “soft” cartilage, termed “meniscus cartilage.” The meniscus cartilage sits between the femur and tibia, and is firm and rubbery, almost like a rubber washer. The meniscus acts as a shock absorber and helps disperse force across the knee joint. There are two menisci in the knee, one on the inner side (or medial side of the knee) and one on the outer side (or lateral side) of the knee.

Tears of the meniscus may occur as a result of an acute injury, such as sudden twisting or hyperextension of the knee. Prolonged squatting may also damage the meniscus. Tears can also occur over time with normal wear-and-tear and without a specific injury.

Injuries causing meniscus tears may occur in conjunction with damage to other knee structures, such as the articular cartilage and/or ligaments of the knee.

Symptoms

Symptoms of meniscus tears typically involve sharp pain in the area of the tear. The pain is usually worse with twisting or pivoting of the knee, or with excessive bending. In addition, swelling in the joint and mechanical symptoms (such as locking, catching, or painful popping) may be present. The knee may feel unstable and give out at times. Some patients with meniscus tears experience painful limitation of knee motion.

Diagnosis

The diagnosis of meniscus tears is usually made from a history of the patient’s symptoms and findings from a physical examination. X-rays are reviewed to evaluate the joint for arthritis and other sources of knee pain. A MRI scan reveals the presence and extent of meniscus tears and any associated knee injuries.

Treatment

Treatment of meniscus tears depends on the level of a patient’s symptoms and how much they interfere with normal activities. Mensicus tissue is largely devoid of any blood supply and therefore will not “heal” similar to cuts in the skin or a broken bone. However, for patients with no symptoms, no formal treatment is necessary. For patients who experience pain in the knee and mechanical symptoms, surgical treatment is often recommended. The procedure is performed arthroscopically and in a minimally-invasive manner. Patients usually are allowed to put full, unrestricted weight on the knee after surgery with quick resumption of normal activities after a brief period of rest.

Depending on the location of the tear, pattern of the tear, and age of the patient, surgical treatment options include repair of the torn meniscus (termed “meniscus repair”) or removing and trimming the torn portion of the meniscus and leaving healthy meniscus tissue intact (termed “partial meniscectomy”).

Additional Information

For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00358.