The difference between synovitis and meniscus injury is mainly in the etiology, symptoms, and imaging tests. 1. Causes: The causes of synovitis include infection, trauma, immunity, metabolism, etc., while meniscus injury is mainly due to indirect violence such as knee twisting or long-term weight-bearing injury. 2. Symptoms: Symptoms of synovitis are mainly swelling and pain, accompanied by fever and limited joint movement. The symptoms of meniscus are not only pain and swelling, but also joint popping and interlocking. 3. Imaging examination: the imaging examination of synovitis shows joint effusion, etc., while the imaging examination of meniscus injury, taking X-ray as an example, can see that the joint space becomes enlarged. If joint pain or swelling occurs, it is recommended to consult a doctor in time to confirm the cause of the disease after examination by a doctor, and actively carry out treatment.