The meniscus is a small piece of cartilage that lays between the femur and tibia in the knee. There are two menisci, one on the medial side of the knee, one on the lateral side of the knee. The main function of the meniscus is to act as a cushion and increase the surface area for the cartilage of the knee.
Tears of the meniscus are one of the most common sports injuries, and occur by twisting, pivoting, cutting or decelerating in athletes. A meniscus tear can also occur in combination with ACL tears or cartilage injuries. In older patients, the cartilage in the meniscus can become weakened, and the meniscus can tear with very minor trauma.
Meniscal tears usually occur with a sudden twist of the knee. Patients often feel a pop in their knee, and have pain at the site of the tear.
Symptoms and Diagnosis
During the 24 hours following the initial injury, the knee will become swollen, and it may become difficult to move the knee. Some meniscal tears cause locking of the knee, where the knee gets stuck in a certain position and needs to be manually manipulated in order to unlock the knee. There is often tenderness along the joint line.
The diagnosis of a meniscus tear can often be made by the history of the injury and the physical exam. In patients who have a suspected meniscus tear, an MRI is usually obtained to confirm the diagnosis and to evaluate the knee for any other injuries.
The initial treatment of many meniscal tears is non-surgical. Rest, ice, elevation is usually used to decrease the symptoms of the meniscus tear. Once the swelling has decreased, physical therapy is often used to increase the strength of the muscles around the knee (quadriceps and hamstrings) and further decrease symptoms.
Surgical treatment of meniscus tears is reserved for patients who have persistent pain and difficulties performing daily activities or sports after the diagnosis of a meniscus tear. The surgery is performed arthroscopically, and done on an outpatient basis. Depending on the size and location of the tear, the torn portion of the meniscus is either repaired or debrided.
Recovery following meniscus surgery usually consists of a short period on crutches, followed by rehabilitation of the injured knee. Most patients can resume their normal activities within two months following surgery.
Written by Brian Feeley, MD Last Reveiwed & Updated by Joe Smith, January 2009