A torn meniscus is a tear in the cartilage of the knee. The meniscus functions to improve the fit between the femur (thigh bone) and tibia (leg bone). The meniscus can tear from either trauma or injury from degeneration. The knee is made up of the femur (thigh bone), the tibia (leg bone) and the patella (kneecap). Ligaments hold the bones of the knee together and the patella lies in the quadriceps muscle in front of the knee. Between the femur and tibia are two pads, one on the medial (inner) and one on the lateral (outside) of the knee. The pads are called the menisci or meniscuses. They are made of fibrocartilage. A torn meniscus can often be diagnosed by a physical exam of the knee. The patient should be referred to an orthopedic surgeon if the pain persists after more than six to eight weeks of conservative care, ice and anti-inflammatory medications. An MRI will most likely confirm the diagnosis as well as the physical exam. Some people think that only athletes can tear a meniscus. This is not true. Even people who don’t consider themselves athletes can tear a meniscus. Some meniscal tears occur during activities of daily living such as getting in and out a car or even just squatting. Menisci can also tear during participation in recreational activities such as skiing, Ping-Pong, dancing or tennis. Tears can occur in people of all ages. Traumatic tears are most common in active people from ages 10-45. Degenerative tears are most common in people age 40 and older. Most people can walk, stand, sit or sleep without pain, but sometimes the pain prevents participation in activities of daily living. Over four to six weeks, the pain and swelling may decrease and activities of daily living may become tolerable. The knee may make extra joint fluid and become swollen. If pain persists, the patient may need to be referred to an orthopedic surgeon for an MRI. Physical therapy, injections and potential surgery may be recommended. The injections may include cortisone injections, platelet-rich plasma injections or stem cell injections.