Synovitis of the knee joint is divided into acute traumatic synovitis and chronic synovitis, with different symptoms. The former is mainly characterized by swelling and pain in the joints, while the latter is mainly characterized by tenderness and swelling of the joints. 1. Acute traumatic synovitis: Mild pain, swelling, and limitation of movement will appear soon after the trauma. A few hours after the injury, fluid will accumulate in the knee joint, and there will be obvious swelling and pain, fever, and so on. 2. Chronic synovitis: there is a history of knee strain or pain, usually manifested as knee joint tenderness, persistent swelling, not dare to do squatting, difficulty in going up and down the stairs and so on. In the long run, muscle atrophy and joint instability may occur. If you suspect synovitis in the knee joint, it is important to seek medical attention in a timely manner.