What is bursitis in the knee? It’s an injury where one of the 14 knee bursae becomes inflamed.
The good news is that most cases of knee bursitis resolve on their own. (1)
Bursae are small fluid-filled sacs. They reduce friction between bones, tendons, and/or skin.
They act as a gliding surface, making our movements smoother.
But, excessive friction can cause swelling on the bursa.
We call this “bursitis.” The suffix “-itis” means that the tissue is swollen.
Below, you have a 101 on knee bursitis. By the end, you’ll know about:
- Septic bursitis
- Prepatellar bursitis
- Pes anserine bursitis
- Infrapatellar bursitis
- Chronic bursitis
- Causes of knee bursitis
- How to diagnose bursitis
- Treatments of knee bursitis
- Ways to prevent an inflamed bursa on the knee joint
Let’s get started!
Top 5 types of knee bursitis and symptoms
1) Septic bursitis
“Septic” means infection. Thus, “septic bursitis” means the bursa is infected.
This can happen if a wound punctures the bursa. The injury lets bacteria in, triggering an infection.
The resulting knee pain and swelling can restrict the range of motion of the joint.
People that kneel often are prone to have an infected bursa. Like plumbers, carpet layers, housemaids, or the clergy. (2)
Males around 50 years of age and athletes are also prone to have a bursitis infection. (2)
Symptoms of septic bursitis
Septic bursitis symptoms are like those of non-infected bursitis (2):
- A swollen lump where the bursa is.
- Knee swelling and joint pain.
- Problems with moving your knee or bearing weight.
- Skin redness and warmth on the affected area.
- Some people may have a fever.
2) Prepatellar bursitis
Prepatellar bursitis affects the prepatellar bursa. This bursa sits on top of the kneecap, between the bone and the skin.
That location makes it prone to inflammation after prolonged kneeling.
That’s why it’s also known as “housemaid’s knee” or “carpet layer’s knee.” Those occupations require kneeling for long periods on hard surfaces. (3)
The pain and swelling are on top of the kneecap. The knee may look like a balloon due to the inflammation.
The level of pain varies, but it usually lets you bend your knee.
Prepatellar bursitis tends to be a temporary condition. It improves with rest and can be prevented.
More about preventative measures further down this article.
3) Pes anserine bursitis
The “pes anserine” area is on the inner side of the knee. It has three tendons:
- The semitendinosus – one of the hamstring muscles.
- The gracilis.
- The sartorius.
The pes anserine bursa is sandwiched between the bone and those tendons.
The inflammation of this bursa causes pes anserine bursitis.
This swollen bursa causes pain on the inner side of the knee.
It may get worse when standing up from a chair or sitting with your legs crossed. There’s also localized swelling in the area.
It commonly occurs in people with obesity and knee osteoarthritis.
Running and jumping athletes are also prone to develop this type of bursitis. (4)
4) Infrapatellar bursitis
Infrapatellar bursae are below the kneecap. We have two of them:
- The superficial infrapatellar bursa, on top of the patellar tendon.
- The deep infrapatellar bursa, under the patellar tendon.
Both reduce the friction of the tendon. This helps us bend and straighten our knees smoothly.
The superficial can become inflamed after prolonged kneeling. Like with the prepatellar bursa.
But, this condition is known as “clergyman’s knee.” Priests are prone to develop it.
For the deep bursa, the most common cause of inflammation is a previous inflammatory disease. Like arthritis or gout. (5)
5) Chronic bursitis
This is long-term bursitis.
Chronic bursitis can be caused by repetitive stress on the bursa. The bursa adapts to the pressure over time.
This process is often painless but creates a big lump on the site of bursitis. (6)
Further reading: 7 different types of knee bursitis and their treatments.
What causes bursitis in the knee joints?
Jobs that require prolonged kneeling can cause knee bursitis. That’s why the colloquial names of certain types of bursitis include the occupation:
- Housemaid’s knee: prepatellar bursitis.
- Clergyman’s knee: infrapatellar bursitis.
- Student’s elbow: bursitis in the elbow.
- Weaver’s bottom: bursitis in the sit bone.
Some athletes can develop bursitis on the pes anserine area. That’s common in running and jumping sports due to overuse.
Active people may also develop septic bursitis. The most common site is on the prepatellar bursa, after falling on their knees.
A strain injury may affect close knee bursae as well.
Some health conditions
- Rheumatoid arthritis.
- Wear and tear in the knees.
- Psoriatic arthritis.
How to diagnose knee bursitis?
To diagnose knee bursitis, your healthcare provider will ask some questions like (6):
- When and how did the swelling start?
- What symptoms do you have?
- What have you done to improve your symptoms?
- What’s your medical history?
Then, they’ll do a physical exam. They will check the size of the swelling, its warmth, redness, and other signs of bursitis.
After the physical examination, your doctor may ask for diagnostic tests. Like a blood test or an analysis of the bursa fluid.
This will tell them if it involves infection. If so, the tests will show which bacteria is causing it. That way, you’ll have the right antibiotics. (2)
How to treat knee pain from bursitis
A bursa displaying signs of infection needs antibiotics. If it’s not septic, knee bursitis treatment includes:
Most cases of knee bursitis resolve on their own with basic treatments. First, resting is key.
Bursitis gets worse with friction, so excessive movement can cause setbacks.
Also, pay attention to your pain and swelling. They will tell you when to move more and when to take a break.
Second, reduce the symptoms. You can manage pain and inflammation at home with these:
- Wrap an ice pack around your knee with compressive wrap. Compression and ice can reduce symptoms.
- Take an anti-inflammatory medication.
Try this: Home treatments for bursitis in the knee.
A physical therapist will give you professional medical advice. They can help you treat inflammation and reduce pain.
He/she will also recommend other treatments to speed your recovery. And give you tips on how to prevent bursitis too.
A physical therapist can help you get back to your athletic activity. If that’s what you’re looking for, find a PT specialized in sports medicine.
If you need help with it, we can connect you with a qualified physical therapist in your area.
Further reading: What to expect from a physical therapy session for knee bursitis
This is an option when medication can’t reduce symptoms after 7-14 days.
It consists of injecting a corticosteroid drug to reduce swelling. This can provide short-term pain relief as well. (1)
But, the risk is that the injection can cause an infection. The syringe may introduce bacteria, worsening the bursitis. (1)
Surgery for knee bursitis depends on the symptoms. Also, how long have you been with the injury.
Orthopaedic surgeons may decide to perform surgical drainage. This will remove the excess fluid while keeping the bursa.
If that doesn’t work, surgeons may consider removing the fluid-filled sac. The following situations may improve with surgery (1):
- Conservative treatment isn’t working.
- Surgical drainage didn’t improve symptoms.
- Need to assess whether surrounding tissues are affected.
How to prevent knee bursitis?
Avoid kneeling for long periods.
If you have to do it due to your job, take breaks often. This will reduce inflammation in the small fluid-filled sac.
Also, try wearing knee pads while working. They can reduce the pressure on the bursa.
This can help: A knee brace can help your bursitis in these scenarios.
Strengthen your legs.
Strengthening exercises can reduce the pressure on the bursa. They can promote recovery and keep your knee joint tissues healthy as well.
This can prevent a future episode of bursitis.
If you’re not used to exercising, gradually increase your level of physical activity.
Keep a healthy weight.
People with a BMI >25 are prone to develop some types of bursitis. For people above that range, losing weight can be a strategy to prevent bursitis. (4)
Does knee bursitis go away?
Yes, it goes away for most people. The key is to let the bursa heal. Avoid activities that increase the friction and don’t push through the pain.
Is walking good for bursitis in the knee joints?
Yes, if it doesn’t make your knee bursitis worse.
If your bursitis feels worse while walking, that’s a sign to rest. That means there’s too much friction on the bursa for the moment.
What causes knee bursitis to flare up?
There are several causes of knee bursitis flare-ups. The most common are repetitive motions and kneeling often.
Certain inflammatory conditions can also trigger a flare-up. Like rheumatoid arthritis, gout, or arthritic psoriasis.
Conclusion: What is knee joint bursitis?
Knee bursitis is a condition where a bursa gets inflamed. This can be painful, but most of the time it resolves on its own.
There are several types. The most common is prepatellar bursitis. Most of them heal with rest and some home remedies.
If you want to recover fast from bursitis, go to a physical therapist.
They will give you exercises to help you heal and teach you what to do to prevent future episodes.
- Lohr, Kristine. “Bursitis: Practice essentials.” [Updated 2020 Dec 11]. Medscape. Retrieved on August, 2021 from: https://emedicine.medscape.com/article/2145588-overview
- Truong J, et al. “Septic Bursitis.” [Updated 2021 Jan 22]. StatPearls. Retrieved on August, 2021 from: https://www.ncbi.nlm.nih.gov/books/NBK470331/
- Rishor-Olney C R, Pozun A. “Prepatellar Bursitis.” [Updated 2021 Feb 22]. StatPearls. Retrieved on August, 2021 from: https://www.ncbi.nlm.nih.gov/books/NBK557508/
- Mohseni M, Graham C. “Pes Anserine Bursitis.” [Updated 2021 Jul 18]. StatPearls. Retrieved on August, 2021 from: https://www.ncbi.nlm.nih.gov/books/NBK532941/
- Jain, Mantu et al. “Infrapatellar bursitis presenting as a lump.” BMJ case reports vol. 14, 5 e243581. 25 May. 2021, doi: 10.1136/bcr-2021-243581
- Williams CH, Jamal Z, Sternard B T. “Bursitis.” [Updated 2021 Jan 17]. StatPearls. Retrieved on August, 2021 from: https://www.ncbi.nlm.nih.gov/books/NBK513340/