Which condition is characterized by localized anterior knee pain associated with swelling?

Localized anterior knee pain associated with swelling is typically characteristic of prepatellar bursitis, commonly referred to as "housemaid's knee." This condition arises due to inflammation of the prepatellar bursa, which is located between the skin and the kneecap (patella). When this bursa becomes inflamed, often due to repetitive kneeling, trauma, or infection, it leads to localized swelling at the front of the knee, along with accompanying pain.

The swelling in prepatellar bursitis is usually prominent because the bursa is a fluid-filled sac, and when it becomes inflamed, it can produce excess fluid. Patients often report a noticeable lump over the kneecap, which can be tender to touch. The pain is typically exacerbated by kneeling or pressure directly over the bursa.

In contrast, other conditions listed may present differently. For instance, patellar tendinitis usually leads to pain at the tendon just below the kneecap rather than localized swelling. Plica syndrome is more about irritation of a fold in the synovial membrane, while chondromalacia patellae involves degeneration of cartilage under the kneecap, leading to pain that often worsens with activities like squatting or stair climbing but