A meniscus tear is a common injury to the cartilage that stabilizes and cushions the knee joint. The type of the tear camera.gif can determine whether your tear can be repaired. Radial tears sometimes can be repaired, depending on where they are located. Horizontal, flap, long-standing, and degenerative tears—those caused by years of wear and tear—generally cannot be repaired.
A torn meniscus generally produces pain in the region of the tear and swelling in the knee joint. These symptoms are made worse with pivoting motions, squatting, and vigorous activities. Torn meniscus fragments can get caught in the knee joint and cause catching sensations. If a large enough fragment becomes lodged between the bearing surfaces, the knee may ‘lock’ and become unable to be fully bent or extended.
Meniscus tears are described by the tear pattern. Tears occur in either the horizontal or vertical direction, or a combination of both. Although the goal of meniscus surgery is to preserve healthy meniscus tissue, many types of tears are not repairable. A meniscus tear requires a blood supply to heal, and since only the peripheral third of the meniscus has it, repairs are generally limited to the peripheral region. Please see arthroscopic meniscectomy for more information.
Injuries to the articular (gliding surface) cartilage can also cause pain, swelling and catching symptoms in the knee. An experienced surgeon can often distinguish between the two conditions with a thorough history and physical exam, but MRI can be useful as well. These two conditions can occur together and are most accurately diagnosed by arthroscopy. Please see articular cartilage injuries for more information.
Meniscus tears are common in active participants of sports, which require cutting and pivoting. In the United States, there are an estimated 850,000 meniscus surgeries performed each year. The meniscus on the side closest to the other knee (medial) is torn more frequently, and men injure their meniscus more often than women.
A torn meniscus is diagnosed with a thorough history and physical exam. Traumatic meniscus tears often occur with twisting type or hyper-flexion injuries. Physical exam maneuvers that reproduce these symptoms may include squatting and rotational manipulations. MRI is useful to confirm the diagnosis, but the most accurate test is diagnostic arthroscopy.