Tears of the meniscus can occur acutely, or be degenerative in nature. An acute tear frequently has an underlying episode of trauma or injury. A chronic tear or degenerative tear can occur without any specific injury or after a minor episode of trauma. In both situations, there would be swelling (effusion) of the knee and knee pain usually localized to the site of the meniscus tear. Currently, it is common to get an MRI of the knee to confirm the tear. Once a symptomatic tear is confirmed, arthroscopic treatment of the meniscus tear is a good option, combined with a rehabilitation program usually involving a physiotherapist.