Knee effusion, commonly known as water on the knee, refers to the accumulation of fluid within the knee joint, resulting in swelling, stiffness, and discomfort. This condition can occur due to inflammation, injury, or underlying joint disorders. The excess fluid may be a result of synovial fluid, which normally lubricates the joint, increasing in volume due to irritation or damage. Causes of knee effusion include acute injuries such as ligament sprains or meniscal tears, chronic conditions like osteoarthritis or rheumatoid arthritis, and infections within the joint. Other potential causes are gout, pseudogout, or bursitis, where inflammation occurs in the bursa, a small fluid-filled sac that cushions the knee joint.
Treatment for knee effusion focuses on addressing the underlying cause and managing symptoms. Initially, rest, ice application, compression with an elastic bandage, and elevation of the affected leg can help reduce swelling and discomfort. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen may be used to alleviate pain and inflammation. In cases where fluid accumulation is significant, a healthcare provider may perform an arthrocentesis, or joint aspiration, to remove excess fluid and relieve pressure. This procedure can also help diagnose the cause of effusion by analyzing the fluid for signs of infection, crystals, or blood. If an underlying condition like arthritis or gout is identified, specific treatments such as disease-modifying medications or dietary changes may be necessary. Physical therapy can also be beneficial in strengthening the muscles around the knee and improving joint function. Proper management of the underlying condition and following a comprehensive treatment plan can help reduce knee effusion and prevent recurrence.
