TLDR: Prepatellar bursitis is swelling of the small fluid sac between your kneecap and skin. It is often caused by kneeling, a fall, or infection. Most cases get better with rest, ice, and knee pads. Infected cases need quick care and may require a needle aspiration, antibiotics, or surgery. Patients in Franklin, Brentwood, Nashville, and across Middle Tennessee can be seen for prepatellar bursitis at the Bone and Joint Institute of Tennessee.
What Is Prepatellar Bursitis?
Prepatellar bursitis is one of the most visible knee problems I see in clinic. The prepatellar bursa is a thin sac filled with fluid. It sits between the front of your kneecap and your skin. Its job is simple. It lets the skin slide over the patella as your knee bends.
When this bursa gets irritated or infected, it fills with extra fluid. The result is swelling on the front of the knee. Patients often describe it as a soft, egg-sized lump. You may have heard it called “housemaid’s knee” or “carpet layer’s knee.” These names point to the jobs most often linked to this knee bursitis.
At the Bone and Joint Institute of Tennessee, I treat both new and long-standing cases. Some patients wake up with kneecap swelling after a fall. Others come in with months of off-and-on swelling tied to their job. Both types are common. Both have good treatment options.
What Causes Prepatellar Bursitis?
The bursa gets inflamed from repeated pressure, sudden trauma, or bacteria. Here is what I tell my patients about the most common causes.
Repetitive Kneeling and Pressure
Most cases I see come from prolonged kneeling. Jobs that raise the risk include:
- Flooring and carpet installers
- Plumbers and electricians
- Roofers and construction workers
- Gardeners and landscapers
- Tile setters and concrete finishers
- Mechanics working on lower car parts
Hobbies like gardening, scrubbing floors, or long prayer can do the same. The steady pressure causes small injuries to the bursa. The bursa responds with swelling.
Direct Trauma to the Kneecap
A hard fall onto the front of the knee can break small blood vessels in the bursa. This causes bleeding and fast kneecap swelling within hours. I see this often in athletes who play contact sports. It also happens after home falls and car crashes.
Infection (Septic Bursitis)
A smaller group of patients develops septic prepatellar bursitis. Bacteria, most often Staphylococcus aureus, enter the bursa through a small cut or scrape. This is a true infection, not just inflammation. It needs medical care right away.
Underlying Health Conditions
Some health issues raise the risk of knee bursitis. Gout, rheumatoid arthritis, and diabetes can lead to chronic flare-ups. Patients on blood thinners may also bleed inside the bursa after a minor bump.
What Are the Symptoms of Prepatellar Bursitis?
The signs are hard to miss. Most patients walk in pointing at a clear lump on the front of the knee. Common symptoms include:
- Soft, fluid-filled swelling over the kneecap
- Tenderness when pressing on the front of the knee
- Mild to moderate pain with kneeling or deep bending
- Warmth and redness in some cases
- Less range of motion when swelling is large
- A feeling of fullness on the front of the knee
One key point I share with patients is that prepatellar bursitis does not cause deep, inside-the-knee pain. The pain stays on the surface, right over the bursa. Pain inside the joint usually points to other problems. These include arthritis, meniscus tears, or ligament injuries.
How Do You Tell the Difference Between Inflamed and Infected Bursitis?
This is one of the most important questions I answer in the office. Getting it right matters. The treatments are very different.
Signs of simple inflammation include slow swelling, mild tenderness, normal skin color, no fever, and the ability to bend the knee.
Signs that point to infection include:
- Fast swelling over 24 to 48 hours
- Heat that feels hot to the touch
- Bright red skin spreading past the kneecap
- Fever or chills
- Severe pain even at rest
- A recent cut, scrape, or puncture near the knee
- Red streaks running up the thigh or down the calf
If you have any of these signs, do not wait. Septic bursitis can spread to nearby tissues or the bloodstream. Same-day care is the right choice.
How Is Prepatellar Bursitis Diagnosed?
Diagnosis starts with a careful history and exam. I ask about your job, recent injuries, hobbies, past flare-ups, and any health issues. The exam looks at the size and feel of the swelling, skin color, range of motion, and tenderness.
In many cases, no scans are needed. When the diagnosis is unclear or infection is a concern, I may order:
- X-rays to rule out a fracture or bone problem
- Ultrasound to confirm fluid in the bursa
- MRI in chronic or unusual cases
- Bursal aspiration with fluid testing when infection is suspected
Sending the fluid to the lab gives key answers. We check the white blood cell count. We look for bacteria under the microscope. We grow a culture to find any germs present. This helps me pick the right antibiotic.
What Are the Treatment Options for Prepatellar Bursitis?
Treatment depends on whether the bursitis is from inflammation or infection. Most patients I treat fall into the first group. They recover well with simple care.
Conservative Treatment for Aseptic Bursitis
For non-infected cases, I use a clear plan that works well:
- Activity changes. Stop the kneeling or pressure that caused the problem. This one step often helps more than any medicine.
- Ice and compression. Apply ice for 15 to 20 minutes a few times a day. Wrap the knee with a sleeve to lower fluid buildup.
- Elevation. Keep the leg raised when you can. This matters most during the first 48 to 72 hours.
- NSAIDs. Over-the-counter medicines like ibuprofen or naproxen reduce pain and swelling. Use as directed. Check with your doctor if you have kidney issues, ulcer history, or take blood thinners.
- Protective padding. Knee pads with thick foam or gel are a must for patients who must keep kneeling at work.
Aspiration
When swelling is large or unclear, I drain the fluid with a small needle in the office. This is called aspiration. It eases the pressure, lets the bursa heal, and gives a fluid sample if infection is a concern.
Treatment for Septic Bursitis
A confirmed or suspected infection needs a different plan:
- Antibiotics aimed at the germ found
- Repeated aspirations to drain the infected fluid
- Hospital care in severe cases
- Surgical drainage when other care does not clear the infection
- Bursectomy, or surgical removal of the bursa, for chronic infections
Surgical Bursectomy for Chronic Cases
A small number of patients have chronic, recurrent bursitis even with good care. For them, I sometimes suggest a bursectomy. This is an outpatient surgery. The damaged bursa is removed. The body then forms a new, healthier bursa over time. Recovery takes four to six weeks. Most patients return to normal activity without further issues.
How Long Does Prepatellar Bursitis Take to Heal?
Most simple cases clear up within two to four weeks with rest and care. Larger fluid buildups or major trauma may take six to eight weeks. Septic bursitis often needs several weeks of antibiotics and close watch. Full healing can take two months or more in those cases.
Repeat flare-ups are common in patients who go back to heavy kneeling without pads. This is why I spend time at follow-up visits talking about prevention. We tailor the plan to each patient’s job and lifestyle.
How Can You Prevent Prepatellar Bursitis?
Prevention is simple and works. I tell patients to:
- Wear padded knee pads during any kneeling task
- Take breaks to stand and stretch when work needs kneeling
- Use a thick foam cushion when gardening or doing floor work
- Treat skin injuries near the knee right away to prevent infection
- Manage health issues like gout, diabetes, and arthritis
- Strengthen the muscles around the knee for better support
For patients who must kneel at work, I often suggest higher-quality knee pads with gel inserts. The cost is small compared to lost time from flare-ups.
When Should You See an Orthopedic Specialist?
Most mild cases of prepatellar bursitis can be managed at home for a few days. But you should see a doctor if:
- Swelling does not get better within seven to ten days of rest and ice
- Pain is severe or stops daily activities
- Swelling is large, hot, or red
- You have fever, chills, or feel unwell
- You have repeat episodes of knee bursitis
- You had prior knee surgery or joint replacement
Get Expert Care for Knee Pain in Middle Tennessee
Prepatellar bursitis is very treatable. Proper care makes all the difference. If you have lasting knee swelling, repeat flare-ups, or signs of infection, do not wait to get checked.
Dr. Cory Calendine is a board-certified orthopedic surgeon and joint replacement specialist. He serves patients across Franklin, Brentwood, Nashville, and Middle Tennessee. Schedule a consultation at the Bone and Joint Institute of Tennessee to build a care plan that fits your needs.
This article is for education only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for any medical concern. Individual results vary based on personal health.
