Meniscus tears of the knee are a very common knee condition seen in patients of all ages. The meniscus is a fibrocartilage crescent shaped structure within the knee that functions as a shock absorber as well as provides stability to the knee. The knee contains two menisci, the medial meniscus (inside aspect of knee) and the lateral meniscus (outside aspect of knee). The medial meniscus is torn much more commonly than the lateral meniscus. Meniscus tears as a result of trauma or injury are common in younger patients involved in sports. Meniscus tears can also occur without trauma as a result of degenerative changes in older individuals; these degenerative meniscus tears often coexist with osteoarthritis.
Patients with a meniscus tear may present with a history of twisting injury to the knee or with atraumatic gradual onset of symptoms localized to one side of the knee. Patients may complain of sharp pain with walking, kneeling, squatting or other activity. Patients may report knee swelling and note mechanical knee catching, locking or giving way. Physical examination of the knee may show an effusion (swelling) and usually demonstrates joint line tenderness in the area of the meniscus tear. Plain X-rays of the knee may be normal in patients with a meniscus tear. A magnetic resonance imaging (MRI) scan is often useful in diagnosing a meniscus tear.
Treatment of meniscus tears depends on many factors including patient age, patient activity level, severity and type of symptoms, and presence of coexisting conditions. In active individuals with a symptomatic meniscus tear and without significant arthritic disease, knee arthroscopy can provide excellent relief of complaints. In more sedentary individuals with degenerative meniscus tears other treat- ments such as medication or joint injections may be considered. Older patients with advanced osteoarthritis and meniscus tears may consider joint replacement surgery. An evaluation by an orthopedic surgeon is necessary to properly diagnose and treat a knee meniscus tear.