Overview
Prepatellar bursitis is irritation and inflammation of the prepatellar bursa, a small fluid-filled sac in front of the kneecap. It usually causes localized swelling and tenderness over the kneecap because the bursa becomes overloaded or injured, often from repeated kneeling or a direct blow. The inflamed bursa can thicken and feel firm, and in some cases it can become infected, which may lead to warmth and fever. Most cases are treated successfully without surgery.
Symptoms
Patients typically notice a soft or firm swelling directly in front of the kneecap that may feel warm and tender. Pain often worsens with kneeling, bending the knee, or pressing on the front of the knee. Some people also feel stiffness and reduced comfort with activities that involve prolonged knee flexion. If the bursa becomes infected, symptoms may include significant warmth, worsening redness, fever, and increasing pain.
Causes
Prepatellar bursitis commonly develops after repeated friction or pressure on the front of the knee, especially from kneeling on hard surfaces. A single direct impact to the kneecap can also injure the bursa and trigger inflammation. Less commonly, the condition can be caused by infection from skin breaks near the knee, or by other inflammatory conditions that increase bursal irritation.
Risk Factors
The biggest risk factor is frequent or prolonged kneeling, such as certain trades, gardening, or household tasks. Direct trauma to the kneecap and activities that repeatedly bump or rub the front of the knee can increase risk. People with skin conditions or minor cuts near the knee, diabetes, or weakened immune systems may be more likely to develop infected bursitis.
Prevention
To reduce risk, use kneepads or cushioning when kneeling and avoid long periods of direct pressure on the front of the knee. Keep surfaces padded during home or work tasks and change positions frequently to reduce friction and overload. After an episode, gradually return to activity and use protection for the kneecap area until tenderness and swelling fully settle.
How the Diagnosis Is Evaluated
Clinicians usually diagnose prepatellar bursitis based on your history of kneeling or injury and a focused physical exam of the swelling over the kneecap. The exam typically assesses tenderness, warmth, redness, range of motion, and whether the swelling is soft, fluid-like, or more firm. If infection is a concern, aspiration of the bursal fluid may be performed and sent for laboratory testing. Imaging such as ultrasound or X-ray is sometimes used if the diagnosis is unclear or if an injury such as a fracture or other soft tissue problem is suspected.
Nonsurgical Treatment Options
The first step is reducing pressure and irritation by resting the knee and avoiding kneeling or direct impact on the front of the kneecap. Ice packs and nonsteroidal anti-inflammatory medications may help decrease pain and inflammation when appropriate for you. Compression and elevating the leg can support comfort in mild to moderate cases. If the swelling is significantly limiting or not improving, a clinician may aspirate the bursa to remove fluid and sometimes relieve pressure. If infection is present, treatment includes appropriate antibiotics, and aspiration may be used to confirm the cause. Corticosteroid injection may be considered in noninfected cases that do not improve with initial conservative care, typically after infection has been ruled out.
When to Seek Medical Attention
Seek prompt medical attention if you have fever, rapidly worsening redness or warmth, severe pain, or you feel ill, because this can suggest infected bursitis. Get urgent care if you cannot bear weight, the swelling is rapidly enlarging, or you have significant injury with inability to move the knee normally. Also seek medical evaluation if symptoms persist beyond a few weeks despite home care, or if the swelling repeatedly returns.
Frequently Asked Questions
Prepatellar bursitis is inflammation of the bursa in front of the kneecap, while injuries may involve ligaments, tendons, or bone; an exam helps distinguish these.
Many mild cases improve with rest, avoiding kneeling pressure, and anti-inflammatory measures, but persistent or worsening swelling should be evaluated.
Infection is more likely when the area is very hot or increasingly red, pain is worsening quickly, and there may be fever or feeling unwell.
You should not attempt drainage at home because it can introduce infection or worsen inflammation.
Improvement often occurs over days to weeks with conservative treatment, but chronic or recurrent cases may take longer.
Next Steps
If your swelling is mild and you can move your knee comfortably, begin by avoiding kneeling pressure, using ice, and considering anti-inflammatory pain relief if safe for you. If the swelling is worsening, very hot or red, or accompanied by fever, arrange prompt medical evaluation. If symptoms persist beyond a few weeks or keep returning, get a clinician's assessment to confirm the diagnosis and discuss targeted conservative care.