M23.10: Discoid meniscus (congenital): Multiple sites

You have discoid menisci.

In the knee joint, the thighbone (femur) is connected to the shinbone (tibia). Between the two bones are two pieces of crescent-shaped cartilage. These pieces of cartilage and fiber are the menisci. There is a medial meniscus and a lateral meniscus. The medial meniscus is on the inside of the leg, while the lateral meniscus is on the outside of the leg. The menisci perform various functions. They balance out any unevenness in the joint surfaces of the bones. The menisci also act as shock absorbers. They absorb violent shocks.

A discoid meniscus is a congenital mutation of the meniscus. Both your medial and lateral menisci have this mutation. There are different types of discoid meniscus. A discoid meniscus may be thicker than a normal meniscus. It is then shaped like a disc, or almost like a disc, rather than like a crescent. But we also refer to a discoid meniscus when a normally shaped meniscus is not properly attached in the knee. A meniscus of this type can easily slip out.

A discoid meniscus may prevent the knee from being properly flexed. You may also feel a click when you move your knee. The knee can be painful or swell up. The inside of the knee may also become inflamed.