Knee arthroscopy is a common procedure where the inside of the knee is viewed using a small high definition camera, often called an arthroscope. The scope is inserted through small incisions in the knee. The images taken through the scope (which is about the size of a pencil) are then projected onto a monitor that allows the knee surgeon to view the knee in greater detail. If the knee needs repair, a surgical instrument is inserted in one of the incisions and while using the scope as a guide, the surgeon will repair the damaged portion of the knee. Knee arthroscopy is often used to treat the torn meniscus, ACL reconstruction, trimming torn pieces of articular cartilage or removing loose bodies.