<unk> , also known as housemaid's knee, is a common cause of swelling and pain above the patella (kneecap), and is due to inflammation of the<unk>  bursa. This structure is a superficial bursa with a thin synovial lining located between the skin and the patella. The bursa develops within the first years of life as a result of mechanical pressure and friction, and it serves the purpose of reducing friction on underlying structures and allowing maximal range of motion in the knee.
Aseptic<unk>  is commonly caused by repetitive work in a kneeling position, hence the name "housemaid's knee".
Inflammation of the<unk>  bursa may be aseptic (most common) or septic (e.g. bacterial infection), the septic variants being most common in children and immunocompromised individuals.<unk>  is more common in men than women.
Prepatellar bursitis
Retrocalcaneal bursitis
Olecranon bursitis
Dislocated patella
Calcific tendinitis
Subacromial bursitis
Tenosynovitis
Chondromalacia patellae