Prepatellar bursitis, commonly known as "housemaid's knee" or "carpenter's knee," is an inflammation of the prepatellar bursa—a small, fluid-filled sac located right in front of the kneecap. This bursa acts as a cushion, allowing the skin to slide smoothly over the bone. When it becomes irritated, it overproduces fluid, leading to visible swelling.
The most striking feature of prepatellar bursitis is the localized swelling on the front of the knee.
Significant Swelling: A soft, fluid-filled lump directly over the kneecap.
Tenderness: Pain when pressing on the kneecap or when kneeling.
Limited Range of Motion: Difficulty fully bending the knee due to the tight feeling caused by the fluid.
Redness and Warmth: If the bursa is infected (septic bursitis), the skin may become hot, red, and painful to the touch.
Fever/Chills: Systemic symptoms suggest an infection that requires immediate medical attention.
Physical Exam
Aspiration: Using a needle to draw fluid from the bursa. This is the most definitive way to check for infection or gout crystals.
X-rays: Usually appear normal, but are used to rule out a kneecap fracture or bone spurs that might be irritating the bursa.
Blood Tests: If an infection is suspected, doctors may look for an elevated white blood cell count.
Treatment depends heavily on whether the bursa is "sterile" (from friction) or "septic" (from bacteria).
Activity Modification: Avoiding kneeling or any direct pressure on the front of the knee.
RICE Protocol: Rest, Ice, Compression (with an elastic wrap), and Elevation to help the body reabsorb the fluid.
NSAIDs: Medications like ibuprofen to reduce both pain and the inflammatory response.
Knee Pads: Using protective padding for those who must kneel for work (plumbers, gardeners, flooring installers).
Antibiotics: Required if the bursa is infected. This is a medical priority to prevent the infection from spreading.
Corticosteroid Injection: For chronic, non-infected cases, a steroid shot can help reduce the risk of recurrent swelling.
Bursectomy: Surgical removal of the bursa sac if the condition becomes chronic and fails to respond to other treatments.