A Torn Meniscus

By Ben Benjamin, PhD
May 29, 2009

A Torn Meniscus

By Ben Benjamin, PhD
May 29, 2009

Question: A torn meniscus in the knee is characterized by what symptoms?

a. Periodic collapsing of the knee while walking
b. A sense that the knee will collapse when walking
c. "Clicking" at approximately 30 degrees before full extension
d. Periodic sticking of the knee in a bent position
e. All of the above
f. a and d

Answer: e. All of the above

The meniscus is a horseshoe-shaped piece of cartilage that provides a cushion for the femur, which sits on the tibia in the central part of the knee. We have a medial and a lateral meniscus, either of which can tear fully or partially.

When the meniscus is torn, it sometimes folds over on itself or moves too far within the joint, becoming pinched between the two bones. This scenario can cause sudden, severe pain. When this occurs, the person's knee frequently will collapse while walking, but it also may feel as if the knee is collapsing, even when it isn't. Sometimes, a clicking sound will occur with torn cartilage; generally, this happens when the knee is about 30 degrees from being straight. Periodically, the knee gets stuck because the piece of cartilage that is folded over is actually blocking the movement of the knee joint. Usually, the cartilage will move back into place if the person jiggles the knee or moves it in a particular way; this frequently results in pain and swelling that subsides within a few days to a week. The individual feels fine until the next episode.