Infrapatellar Bursitis: What Is It and How Is It Treated?
Infrapatellar bursitis is swelling of a small fluid-filled sac (bursa) just below the kneecap. Treatment usually starts with rest, ice and avoiding kneeling. If symptoms do not go away, imaging can check for deeper causes. These include alignment problems in the leg that put extra load on the knee.
Key points
- A bursa is a tiny cushion between bone and soft tissue. When the one below your kneecap gets irritated, it swells and hurts.
- Repeated kneeling is the most common trigger. This is why the condition is sometimes called clergyman's knee or pastor's knee.
- There are two types: superficial (just under the skin) and deep (behind the patellar tendon).
- Most cases settle with simple measures. But pain that does not go away may point to a leg alignment issue that keeps overloading the knee.
- Standing, weight-bearing imaging can show alignment problems that lying-down scans miss.
You may have swelling or tenderness just below the kneecap that does not go away. If so, the first step is to understand what is happening inside the joint. This page explains what infrapatellar bursitis is, what causes it and how it is managed. It also covers when alignment imaging may be worth considering.
What are the symptoms of infrapatellar bursitis?
The main symptoms are pain, swelling and tenderness just below the kneecap. You may notice a soft, puffy lump at the front of the knee. Pain usually gets worse when you kneel, squat or press on the area.
If your knee is red, hot and very painful, or you feel unwell with a fever, get medical help promptly. This could mean an infection in the bursa (septic bursitis). It needs urgent care from your doctor or a hospital emergency department.
What causes infrapatellar bursitis?
The most common cause is repeated pressure or friction on the front of the knee. The bursa becomes irritated, inflamed and fills with extra fluid. Some people are more at risk because of their work, their sport or the way their legs are aligned.
What is the difference between superficial and deep infrapatellar bursitis?
There are two infrapatellar bursae at the front of each knee. They sit in slightly different places. The difference matters because it affects how the problem feels and how it is investigated.
- Sits just under the skin, in front of the patellar tendon
- Swelling is usually visible and easy to feel
- Caused mainly by direct pressure from kneeling
- This is the classic "clergyman's knee" picture
- Sits behind the patellar tendon, between the tendon and the shinbone
- Swelling is deeper and harder to see from outside
- Often linked to overuse, running or jumping
- Can be confused with patellar tendonitis on examination
How is infrapatellar bursitis different from patellar tendonitis?
Both conditions cause pain just below the kneecap, but they involve different structures. Patellar tendonitis (sometimes called jumper's knee) is irritation of the tendon itself. Infrapatellar bursitis is inflammation of the fluid-filled cushion next to or behind that tendon. Treatment can differ, so getting the right diagnosis matters.
With bursitis, you tend to feel pain mainly when you press on the area or kneel. With tendonitis, pain usually flares during activities that load the tendon, such as jumping, running or climbing stairs. A clinician can often tell the difference by examining you, but imaging helps confirm which structure is involved.
When is MRI more helpful? EOS and weight-bearing imaging are excellent for showing bone position and joint alignment. For soft tissue detail, such as confirming whether a bursa or a tendon is the problem, MRI is usually the better tool. Your clinician can advise which type of imaging you need.
What is the treatment for infrapatellar bursitis?
Treatment usually starts with simple, conservative measures. Most cases improve within a few weeks once the source of irritation is removed.
Common approaches
- Rest and changing your activities. Avoid kneeling or putting direct pressure on the front of the knee.
- Ice. A cold pack applied for short periods can help reduce swelling and pain.
- Knee pads or cushioning. If your work or hobby needs kneeling, padded knee protection can prevent more irritation.
- Anti-inflammatory medicine. Over-the-counter options (taken as directed) may ease pain and swelling. Speak to your pharmacist or doctor.
- Physiotherapy. Targeted exercises can strengthen the muscles around the knee and improve how load is spread.
In persistent or severe cases, a clinician may consider draining the fluid (aspiration) or a corticosteroid injection. Surgery to remove the bursa is uncommon. It is usually kept for cases that do not respond to other measures. Your doctor or specialist will guide you on next steps.
ScanAlign does not provide treatment. It is a diagnostic imaging service. Its imaging and alignment assessment can help your treating clinician understand why the problem keeps coming back.
How does leg alignment affect infrapatellar bursitis?
Your leg works as a connected chain, from hip to ankle. If one part of that chain is out of alignment, the knee can end up taking more force than it should. A slight tilt in the pelvis, a rotated thighbone or a difference in leg length can all change the angle at which your kneecap moves. This puts extra pressure on the bursa beneath it.
This is why some people find their bursitis keeps returning even after treatment. The irritation stops for a while, but the underlying mechanical cause remains.
Why standing imaging matters
Most scans are taken while you lie down. In that position, gravity is removed, muscles relax and your joints settle differently than when you stand. A misalignment that causes problems when you walk or kneel may not show when you are lying flat.
An EOS scan captures your entire leg, from hip to ankle, while you stand. It uses about 90% less radiation than a standard X-ray, around ten times less. Because it images you upright and weight-bearing, it shows the real-world alignment your knee works with every day. This gives your treating clinician a much clearer picture of whether alignment is contributing to your bursitis.
Before you start treatment, or change the one you are on, it is worth getting a detailed diagnosis. Knowing whether the cause sits in the pelvis, the legs or the spine changes what will actually help.
If your infrapatellar bursitis keeps coming back, a standing alignment assessment at our London clinic could reveal a mechanical cause that other imaging has missed.
Book a free video consultationFrequently asked questions about infrapatellar bursitis
Clergyman's knee is another name for infrapatellar bursitis. It means swelling of the bursa just below the kneecap, typically caused by kneeling for long periods on hard surfaces. It is also sometimes called pastor's knee.
Most cases improve within a few weeks once you stop the activity that caused it. Chronic or recurring cases can take longer. They may benefit from further investigation to find an underlying cause.
Low-impact activities like swimming or cycling are usually manageable if they do not cause pain. Avoid exercises that involve kneeling, deep squats or direct pressure on the front of the knee until the swelling settles. Your physiotherapist can help you find safe alternatives.
No. Prepatellar bursitis (housemaid's knee) involves the bursa on top of the kneecap. Infrapatellar bursitis affects the bursa below the kneecap. They are separate conditions, though both can result from kneeling.
No. ScanAlign is a private, self-pay clinic. You can refer yourself without a referral from your doctor or a consultant. Your first step is a free video consultation to discuss whether an alignment assessment is right for you.
For patients travelling from abroad, the price is confirmed during the free video consultation. You can also read the ScanAlign FAQs page.
Yes. EOS uses about 90% less radiation than a standard X-ray, around ten times less. It is a very low-dose imaging system. You can read more on the FAQs page.
Yes. If your leg alignment is off, the knee joint may take uneven forces. Over time, this can irritate the bursae, tendons and other structures around the knee. Correcting the underlying alignment issue may help prevent the bursitis from returning.
You stand inside the EOS scanner in a natural, upright position. The machine captures a full-length image of your skeleton in under a minute. The image is then analysed for alignment from your spine down to your ankles.
See your doctor or go to a hospital emergency department if the knee is very red, hot or swollen, if you have a fever, or if you cannot bear weight on it. These may be signs of infection or a more serious injury that needs prompt attention.
Wondering why your knee bursitis keeps coming back?
A standing alignment assessment can show whether the way your legs move and carry weight is putting extra stress on your knee. Start with a free, no-obligation video consultation from home.
Book a free video consultationRelated reading
Sources
- NHS. "Bursitis." nhs.uk, National Health Service, 2023.
- Rishor-Olney, C.R. and Pozun, A. "Prepatellar Bursitis." StatPearls, National Library of Medicine, 2023.
- Illés, T. and Somoskeöy, S. "The EOS imaging system and its uses in daily orthopaedic practice." International Orthopaedics, 36(7), 2012, pp. 1437–1443.
Written by Abbas Dhami (Specialist Diagnostic Radiographer)
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.