Glossary M

Browse the glossary by selecting a letter or by entering an arthritis-related term:

Magnetic resonance imaging (MRI)

A procedure in which a very strong magnet is used to pass a force through the body to create clear, detailed images of cross-sections of the body.

Medial collateral ligament (MCL)

One of four ligaments that stabilizes the knee. The MCL runs along the inside of the knee joint and keeps the inside of the knee joint from widening too far when the knee buckles. If the MCL is stretched too far, however, it may tear.


A crescent-shaped wedge of cartilage in the knee joint. Tears of the meniscus and surgical removal of torn menisci have been associated with the development of osteoarthritis in the knee.


Fibrous tissue in the body that holds us upright and gives the body movement, including movement that we consciously initiate (such as waving a hand) and movement we are scarcely aware of, such as movement of the blood through the vessels or of food through the digestive system.

Predict Your Joint Pain
weather icon

Predict your joint pain level based on the local weather.