normal-medial-meniscus
A cross-sectional view of a normal knee, looking at the top of your lower right leg. In this illustration, the medial (inside) meniscus is on the left and lateral (outside) meniscus is on the right.

tornl-medial-meniscus

In this illustration,
the medial meniscus is torn

The meniscus is a tissue pad located between your thighbone (femur) and shinbone (tibia). Each knee has two menisci, one on each side, that help to stabilize the joint and distribute load between your upper and lower leg. The ends of your thighbone and shinbone are covered with articular cartilage. This slippery substance helps your bones glide smoothly across each other as you bend or straighten your leg.

 

If your meniscus is degenerated or was damaged or torn, the loose ends may have caused pain and limited your range of motion. Millions of Americans visit physicians as a result of meniscus tears, and 1 million or more end up having a partial meniscectomy – surgical removal of a torn meniscus – which can alleviate pain but results in a high risk for arthritis and future knee replacement.1,2,3 In addition, many people still suffer from continued knee pain that can seriously affect their daily lives. When a surgeon removes these torn or loose ends, it may temporarily resolve symptoms; however, the meniscus is smaller and thinner, putting your knee at risk of being overloaded.

 

Overloading can damage the articular cartilage protecting your knee. As this cartilage wears away, it becomes frayed and rough, resulting in a condition known as osteoarthritis (OA). Osteoarthritis usually develops over a period of many years and typically affects people who are middle-aged or older. Other risk factors for OA include being overweight or previous injury to the affected joint.1

1 Cullen KA, Hall MJ, Golosinskiy A. Ambulatory surgery in the United States, 2006. Natl Health Stat Rep.2009;11:1-25
2 Metcalf MH, Barrett GR. Prospective evaluation of 1485 meniscal tear patterns in patients with stable knees. Am J Sports Med. 2004;32:675-680
3 Roos H, Lauren M, Adalberth T, Roos EM, Jonsson K, Lohamander LS. Knee osteoarthritis after meniscectomy: prevalence of radiographic changes after twenty-one years, compared with matched controls. Arthritis Rheum. 1998;41(4):687-693