Meniscal injuries are graded on MRI, and can generally be classified into three levels on MRI: 1. Grade I meniscal injuries are signals of punctate injuries within the meniscus, usually due to degeneration of the meniscus. 2. Grade II meniscal injuries are signals of striated injuries within the meniscus that do not reach the articular surfaces, and are often due to degeneration of the meniscus, or meniscus degeneration. 3. Grade III meniscal injuries are signals of striated injuries within the meniscus that reach the articular surfaces, and Grade III injuries signal a tear of the meniscus. 4. Grade III injuries are signals of striated injuries that reach the articular surfaces, and grade III injuries signal a tear of the meniscus. The signal of grade III injury is a tear of the meniscus, which is a bar-shaped signal that reaches the articular surface. The signals of grade I and II injuries can lead to mild pain, usually pay attention to avoid meniscus injuries in sports, avoid prolonged squatting work. A grade III tear of the meniscus can often lead to joint popping, cross-locking, and severe pain in the joint, often requiring surgery.