Possible causes of meniscus ringing include degeneration of articular cartilage, meniscus injury, normal popping and so on. 1. Degeneration of articular cartilage: when the articular cartilage degeneration lesions, making direct contact with the articular cartilage surface, causing cartilage wear, wear and tear of the articular cartilage friction each other can appear meniscus ringing. 2. Meniscus injury: when the knee joint is stimulated by trauma or there is sports injury, the meniscus injury can be caused by joint strangulation and rattling. 3. Normal popping sound: there is a small amount of gas and tissue fluid in the knee joint of normal people, and the flow of tissue fluid and gas during the activity may cause the meniscus to rattle, which is a normal phenomenon. Meniscus ringing can be caused by a variety of reasons, it is recommended to improve the knee joint MRI and other tests to clarify the cause of the disease for targeted treatment.