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 ...

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 ...

New MR techniques show that facet joint effusion (the collection of fluid in the spinal joints) and interspinal ligament edema (swelling of the interspinal ligaments) are major sources of lower back ...