Water on the knee, or knee effusion, refers to the buildup of fluid in and around the knee joint. This condition leads to a painful, swollen knee and can be caused by various factors, including ...

If your knee is swollen, it's also called a knee effusion. Swelling happens when fluid builds up in the knee joint. Sometimes a knee effusion is referred to as “water on the knee,” but that is not a ...

Some amount of fluid around your knee is necessary — it helps cushion your bones and keeps the joint limber. But if too much fluid accumulates, it can lead to an effusion (or an abnormal collection of ...

The radiograph shows knee effusion, which can be seen as water density above the patella and anterior to the fibula. The next best step in treatment is to perform arthrocentesis to evaluate the fluid ...