The pre patella bursa is a small fluid-filled sac which sits under the skin, on the front of the knee above the patella (kneecap). Bursa are situated throughout the body (there are over 100 in total) and are located at anatomical ‘hotspots’, where two structures slide over each other in close proximity and there is a potential for unwanted friction.
The role of the bursa is two-fold.
They are responsible for:
- Providing a frictionless surface for motion to occur. The pre patella bursa helps to provide smooth movement between the kneecap and the quadriceps tendon during knee extension (straightening of the knee).
- Providing a protective barrier against direct impact or repetitive tasks. In the case of the pre patella bursa this is to protect the kneecap if you sustain a fall or kneel for a long period of time.
Under normal circumstances the pre-patellar bursa perform their role successfully. However, on occasion they can become inflamed and painful. A painful, swollen pre-patellar bursa is known as pre-patellar bursitis (also known as housemaids knee). This can occur because of:
- Excessive pressure on the bursa from kneeling
- Direct impact on the bursa from a fall
- Secondary to a systematic inflammatory condition such as gout or rheumatoid arthritis
There are two categories of bursitis:
1. Septic bursitis
The is when the bursa gets infected and becomes painful and swollen. Due to its superficial location the pre patella bursa is susceptible to becoming infected. Luckily septic bursitis is relatively rare but it does require medical assistance. It has been reported to be responsible for hospital admissions rates of 1-12 cases per 10,000.
If the bursa looks red and hot (aswell as painful and swollen) you should see your GP as soon as possible as you will require immediate antibiotic treatment. You may also start to feel unwell and experience fever-like symptoms.
The pre patella bursa and the olecranon bursa of the elbow are the most common bursa to get infected. Research has shown the olecranon bursa (at the elbow) to be four times more susceptible to septic bursitis than the pre patella bursa (Baumbach et al., 2012).
2. Aseptic bursitis
This is when the bursa becomes swollen and painful but the bursa not infected, so it is not red aswell. This is, by far, the most common form of bursitis and is regularly associated with one or more of the below risk factors:
- Sex – 80% of all bursitis patients have been reported to be male (Baumbach et al., 2012).
- Age – bursitis can occur at any age however, the highest incidence rate of pre patella bursitis occurs between the fourth and sixth decade of life.
- Repetitive pressure on the bursa during kneeling. This condition is known as housemaids’ knee and is associated with prolonged periods of weight bearing onto the kneecap. It is often seen in occupations such as carpet laying and building.
- Direct impact/trauma to the tip of the kneecap, such as after falling directly onto your knee.
- Rheumatological conditions such as gout or rheumatoid arthritis can cause the pre patella bursa to become inflamed (Sayegh et al., 2014).
How do you know if you have pre patella bursitis?
The hallmark symptoms of pre patella bursitis are pain and swelling on the front of the knee. Symptoms can start rapidly after trauma or can gradually become apparent with repetitive tasks such as working in your knees.
How is pre patella bursitis diagnosed?
Obtaining an accurate diagnosis of pre patella bursitis is essential in providing you with the most appropriate treatment. A doctor or physiotherapist is able to diagnose pre patella bursitis.
The examination includes a:
- Direct questioning is used to uncover how, why, and when your pain started. A full medical history will also be discussed and it is important to rule out a systemic inflammatory causes of your pain such as gout or rheumatoid arthritis and/or an infection.
- Physical assessment includes knee range of movement and strength testing as well as palpation (feeling) of different structures around the knee. This is often sore but it is important to help diagnose the location of your symptoms. You may be asked to perform a series of function tests such as standing on one leg or squatting.
2. Further investigations:
Clinical examination is often able to hypothesise a diagnosis of pre patella bursitis. However, for an accurate diagnosis further investigations maybe required. If we suspect a bursitis is secondary to an infection or a systemic inflammatory condition we will refer you to your GP or a specialist.
The GP or specialist may send you for blood tests and/or further investigations. This may include:
- Blood tests
- If your clinician suspects septic bursitis you may be referred for a series of blood tests.
- If your clinician suspects a systemic cause of your symptoms such as gout or rheumatoid arthritis then blood tests may also be required
- Bursal aspiration
- If a septic pre patella bursitis is suspected a small amount of bursal fluid maybe removed using a needle and sent to pathology laboratory for further investigations. This would only be carried out in a hospital setting.
3. Diagnostic musculoskeletal ultrasound imaging
A diagnostic ultrasound scan will be carried out at your first appointment. An ultrasound scan is regarded as a gold standard imaging technique for assessing the presence of bursal pathology. Research has shown diagnostic ultrasound as a highly effective imaging tool for diagnosing pre patella bursitis (Baumbach et al., 2012). It is also capable of observing inflammatory arthritic conditions such as gout (Fernandez et al. 2017 and Villaverde et al. 2014) and is therefore, an appropriate imaging technique to differentially diagnose the cause of pre patella bursitis.
At Complete our experts are dual trained as physiotherapists and musculoskeletal sonographers. During your initial assessment your clinician will be able to clinically assess your knee and perform a diagnostic musculoskeletal ultrasound scan. After an accurate diagnosis has been made, your clinician will be able to offer you the most effective and appropriate treatment.
How do you treat pre patella bursitis?
Treatment for pre patella bursitis is reliant on an accurate diagnosis and is dependent on whether the bursa is aseptic or septic.
Septic pre patella bursitis
This is treated via your GP or by a hospital consultant. We do not treat these at our clinics. Septic pre patella bursitis requires medical management and a course of antibiotics. Research has shown 82% of all septic bursae require aspiration (Sayegh et al., 2014). During this procedure a needle is used to remove infected fluid within the bursal space. On rare occasions where this fails to resolve symptoms, surgical management may be required.
Aseptic pre patella bursitis
The vast majority of patients with aseptic bursitis respond very well to conservative management. The swelling and pain normally settle within 6 weeks, which often includes:
- Avoidance of aggravating activities and postures including weight-bearing directly on the knee
- Providing an area of padding (knee pad) over the kneecap to reduce pressure on the bursa
- A short course of nonsteroidal anti-inflammatory medication such as ibuprofen or naproxen can help reduce pain and inflammation associated with bursitis (Kennedy et al., 2016)
What if conservative management has not been successful in resolving your aseptic pre patella bursitis?
If you have been diagnosed with aseptic pre patella bursitis and conservative measures have not resolved your symptoms then an ultrasound-guided aspiration and/or a corticosteroid injection may be appropriate for you.
Using ultrasound guidance (and local anaesthetic if required) your clinician will drain (also known as aspirate) the fluid from the bursa. If appropriate a small amount of corticosteroid (also known as steroid) is injected, to ensure the fluid does not return. This is carried out in one short procedure. Corticosteroid is a potent anti-inflammatory medication routinely used to resolve pain and inflammation associated with bursitis.
At Complete we have a team of highly skilled clinicians who are experienced in providing ultrasound-guided procedures for pre-patellar bursitis. All clinicians are fully qualified physiotherapists, musculoskeletal sonographers, independent prescribers and injection therapists. During your consultation, your clinician will perform a full clinical assessment and a diagnostic ultrasound scan. If an injection is indicated, your clinician will be able to prescribe the most appropriate medication for you prior to performing an ultrasound-guided injection. You are able to self-refer directly into our same day service. You do not need to be referred by a doctor or bring a prescription.
If you would like more information or would like to book an appointment please contact us on 0207 4823875 or email firstname.lastname@example.org.
BAUMBACH, S.F., BAUMBACH, S.F., LOBO, C.M., LOBO, C.M., BADYINE, I., BADYINE, I., MUTSCHLER, W., MUTSCHLER, W., KANZ, K. and KANZ, K., 2014. Pre patella and olecranon bursitis: literature review and development of a treatment algorithm. Archives of orthopaedic and trauma surgery, 134(3), pp. 359-370.
FERNANDES, E.D.A., BERGAMASCHI, S.B., RODRIGUES, T.C., DIAS, G.C., MALMANN, R., RAMOS, G.M. and MONTEIRO, S.S., 2017. Relevant aspects of imaging in the diagnosis and management of gout. Revista Brasileira de Reumatologia, 57(1), pp. 64-72.
KENNEDY, S.A. and KENNEDY, S.A., 2016. CORR Insights®: A Randomized Trial Among Compression Plus Nonsteroidal Antiinflammatory Drugs, Aspiration, and Aspiration With Steroid Injection for Nonseptic Olecranon Bursitis. Clinical orthopaedics and related research, 474(3), pp. 784-786.
VILLAVERDE, V., ROSARIO, M.P., LOZA, E. and PÉREZ, F., 2014. Systematic Review of the Value of Ultrasound and Magnetic Resonance Musculoskeletal Imaging in the Evaluation of Response to Treatment of Gout. Reumatología clínica (English Edition), 10(3), pp. 160-163.