This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Housemaid's knee is bursitis of which of the following: September 2010 
Select and explain. 
A. Olecranon bursa, B. Infrapatellar bursa, C. Prepatellar bursa, D. Subacromial bursa
C: Prepatellar bursa
Answer: C: Prepatellar bursa 
Explanation: Ans. C: Prepatellar Bursa Prepatellar bursitis, also known as Housemaid's knee, is a common cause of swelling and pain above the patella, and is due to inflammation of the prepatellar bursa. This structure is a superficial bursa with a thin synol 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 prepatellar bursitis is commonly caused by repetitive work in a kneeling position, hence the name "housemaid's knee