What is a common diagnosis for a swollen knee that resembles the size of a gold ball?

A common diagnosis for a swollen knee that resembles the size of a golf ball is pre-patellar bursitis. This condition occurs when the bursa located in front of the kneecap becomes inflamed and fills with fluid, leading to noticeable swelling. The bursa is a small sac of fluid that helps to reduce friction between tissues in the knee, and when it becomes irritated or injured, it can swell significantly. The characteristic swelling is often localized and can be quite pronounced, resembling the size of a golf ball.

Understanding this condition requires recognizing that it is often caused by repetitive kneeling, direct trauma to the knee, or prolonged pressure, which makes it especially common in certain occupations or activities. The fluid accumulation may present with tenderness and discomfort, especially when bending or putting pressure on the knee.

Other conditions such as osteoarthritis, meniscal tears, and rheumatoid arthritis can also cause knee swelling but typically involve different mechanisms and presentations. Osteoarthritis generally leads to joint degeneration rather than isolated swelling. A meniscal tear may cause joint effusion but is more often associated with mechanical locking or catching sensations in the knee. Rheumatoid arthritis results in a systemic inflammatory response affecting joints bilaterally and usually involves more than just swelling, often accompanied by stiffness and