Gerarts (synonym dropsy joint) - accumulation vpotnye fluid in the joints, mainly large, without the inflammatory process in the surrounding tissues, traumatic or infectious (TB) origin. For hydrarthrosis characterized by a significant increase in joint fluctuation. When hydratase of the knee joint may be running of the patella.
Treatment: arthrocentesis, the extraction of fluids, immobilization. Then treatment depending on the cause of hydratron.