What is the defining characteristic of prepatellar bursitis?

The defining characteristic of prepatellar bursitis is the enlargement of the bursa due to constant irritation, commonly referred to as "housemaid's knee." This condition occurs when the bursa located in front of the kneecap becomes inflamed as a result of repetitive friction or pressure, often from kneeling or prolonged activities that put strain on the knee. The bursa is a small fluid-filled sac that helps reduce friction and allows for smooth movement between tissues, but when it is irritated over time, it responds with inflammation, leading to swelling.

Although excess fluid accumulation in the bursa can occur as a result of this inflammation, the true defining feature is the irritation and subsequent enlargement of the bursa. Bursitis can lead to significant discomfort and restrict movement, yet it is specifically this persistent irritation that characterizes the condition, distinguishing it from other issues that might involve the knee.