Imaging X-ray of the knee of a 12-year-old male, showing knee effusion of medium severity, marked by black arrows. Over time, the body may produce excess joint fluid.ĭiagnosis Skyline view of the patella demonstrating a large joint effusion as marked by the arrowĪlso known as arthrocentesis, this procedure includes withdrawal of fluid from inside the knee for analysis such as cell count, culture for bacteria, and examination for crystals, such as uric acid or calcium pyrophosphate dihydrate ram crystals found in gout or pseudogout. In overweight or obese individuals the body places more weight on the knee joint. Having osteoarthritis or engaging in high-risk sports that involve rapid cut-and-run movements of the knee - football or tennis, for example - means an individual is more likely to develop water on the knee. Prepatellar bursitis (kneecap bursitis).The swelling can, in most cases, be easily cured. The type of fluid that accumulates around the knee depends on the underlying disease, condition or type of traumatic injury that caused the excess fluid. There could also be an underlying disease or condition. Bruising may be seen as bluish lesion.Ĭauses of the swelling can include arthritis, injury to the ligaments of the knee, or an accident after which the body's natural reaction is to surround the knee with a protective fluid. Bearing weight on the knee joint may be impossible and the pain unbearable. If an individual has injured their knee, they may note bruising on the front, sides or rear of the knee. Heat may help relax the muscles of the knee. Fluid may also show under the knee when straightened. When the knee joint contains excess fluid, it may become difficult or painful to bend or straighten. Puffiness around the bony parts of the knee appear prominent when compared with the other knee. One knee may appear larger than the other. Even if one knee is much larger than the other, pain is not guaranteed. Osteoarthritis knee pain usually occurs while the joint is bearing weight, so the pain typically subsides with rest some patients experience severe pain, while others report no discomfort. Signs and symptoms of water on the knee depend on the cause of excess synovial fluid build-up in the knee joint. It has many common causes, including arthritis, injury to the ligaments or meniscus, or fluid collecting in the bursa, a condition known as prepatellar bursitis. Knee effusion, informally known as water on the knee, occurs when excess synovial fluid accumulates in or around the knee joint. Traumatic effusion of the right knee, with swelling lateral to the kneecap marked by an arrow

Fluid around knee