Bursitis is inflammation of a bursa. There are plenty of bursae in the body - approximately 160 in fact. These bursae may become inflamed due to a multitude of reasons, both acute and chronic, which we will discuss.
A bursa is a a sac containing synovial fluid that is located between tendons and bones. Its primary function is to reduce friction during movement as well as to absorb pressure (acting as a cushion) in certain joints.
We will be discussing a few specific forms of bursitis in this document, such as:
- Subacromial bursitis
- Olecranon bursitis
- Prepatellar bursitis
- Infrapatellar bursitis
- Trochanteric bursitis
- Retrocalcaneal bursitis
Pathophysiology
The inflammation of the bursa may occur due to a number of reasons, namely:
- Repetitive use - this places the bursa under increased pressure which leads to injury. This is where the nomenclature housemaid’s knee or student’s elbow derives as the repetitive actions found within these groups.
- Crystal deposition - we will discuss crystal arthropathy in a separate CCC but crystal arthropathy may lead to bursitis as well.
- Autoimmune causes - such as rheumatoid arthritis.
- Infection - may lead to septic bursitis.
All of these lead to infiltration of immune cells with increased capillary permeability, increased exudate collection (leading to swelling), adhesions and inflammation in the connecting joint. Studies have not found histológicas evidence of inflammation, but the inflammatory aetiology is based on the relief provided by anti-inflammatory medications.
⚠️ Risk factors
- Occupation - repetitive stressors may lead to bursitis. We will discuss examples when discussing the specific types below.
- Rheumatoid arthritis
- Osteoarthritis - it is believed that osteophyte deposition may be implicated.
- Crystal arthropathies - such as gout or pseudogout.
- Trauma - penetrating wounds may allow for infection to cause infective bursitis. It is most commonly staphylococci and streptococci but other pathogens may be implicated (such as Pseudomonas, Enterobacter agglomerans, Enterocci faecalis, Haemophilus influenzae and Escherichia coli).
- Anatomical deformities - such as lumbar spondylosis, valgus knee, coracoacromial arch impingement, leg length discrepancy.
😷 Presentation
General symptoms of all bursitises/bursitides include:
- Pain - there will be pain and tenderness at the site of the bursa and there is commonly tenderness on palpation.
- Limited range of motion - especially in active range (range of motion that the patient carries out themselves).
- Swelling - the swelling should be fluctuant.
🔍 Investigations
⭐️ Bursitis is typically a clinical diagnosis based on the symptoms present, history and examination.
We can perform aspiration of burial fluid if suspecting septic bursitis. This is sent for microscopy and culture as well as crystal examination. White cell count and glucose levels of the burial fluid can also be performed. Ideally it should be done prior to beginning empirical antibiotics. Crystal analysis can also be done.
The aspirate appearance can give insight into the diagnosis:
- Pus - likely to be septic.
- Straw-coloured - likely to be non-septic.
- Blood-stained - may be septic or may be due to trauma, gout or rheumatoid arthritis.
- Milky - gout or rheumatoid arthritis.
🧰 Management
Bursitis can be managed through conservative measures. This includes:
- Rest - limit activity and avoid direct pressure on the site.
- Ice - can be used to reduce swelling. Should be applied for 10 minute intervals every few hours. A thin towel should be placed in between the ice and skin to avoid direct contact.
- Compressive bandaging
- Analgesia - with paracetamol or NSAIDs.
If the patient does not respond to conservative measures, we can do the following:
- Aspiration - to reduce the effusion and improve range of motion and comfort.
- Intrabursal corticosteroid injection - only if certain it is non-septic. It is given with a local anaesthetic (often methylprednisolone + lidocaine). This is considered if the patient does not respond to conservative measures and the patient’s activities of daily living are affected.
- Surgery - this is only done in severe cases where it is refractory to treatment. The procedure involves removal of the inflamed bursa (bursectomy).
- Admit to hospital
- Aspirate bursal fluid - for culture.
- Empirical antibiotics - until cultures are known. The common pathogens are staphylococcal and streptococcal infections.
- Flucloxacillin - 500mg 4x daily if ≤70kg. If >70kg it is 1000mg 4x daily.
- Clarithromycin - 500mg 2x daily if allergic to penicillin.
- Erythromycin - 500mg 4x daily if pregnant or breastfeeding.
Let’s now take a look at specific bursitises:
The olecranon bursa overlies the olecranon process on the posterior surface of the elbow.
Olecranon bursitis is most commonly caused by overuse or trauma and as a result is sometimes also known as student’s elbow, draftsman’s elbow or miner’s elbow.
We see it commonly in students and writers, gardeners, mechanics, plumbers, roofers and other occupations that require pressure on the elbows. Repetitive motions of overhead throwing can also lead to olecranon bursitis.
The knee contains 4 bursae anterior to the joint:
- Suprapatellar bursa - between femur and quadriceps.
- Subcutaneous prepatellar bursa - between the skin and the patella
- Subcutaneous infrapatellar bursa - between the skin and tibial tuberosity.
- Deep infrapatellar bursa - between the patellar ligament and superior tibia.
It is this subcutaneous prepatellar bursa that is most commonly affected due to its proximity to the skin surface. As such it is affected by trauma (such as falls or impact on the knee), chronic pressure such as prolonged kneeling.
It is sometimes known as housemaid’s knee or carpenter’s knee.
Greater trochanteric pain syndrome (GTPS) was previously called trochanteric bursitis as it was believed that bursitis was the primary cause of the syndrome. However, it was found later that it is not only the bursae that are affected, but also the tendons, muscles, and fascia. It is often tendinopathies or tears of the gluteus medius and gluteus minimus along with trochanteric bursitis that leads to GTPS.
⚠️ Risk factors
- Soft tissue trauma and overuse are the most common causes of trochanteric bursitis.
It is often co-existent with osteoarthritis, rheumatoid arthritis, iliotibial band syndrome and other issues such as discrepancies in leg length as well as obesity.
😷 Presentation
- Lateral hip pain
- Pain on palpation of the greater trochanter
- Swelling
- Positive Trendelenburg’s sign - this is performed by asking the patient to stand on a single leg. When standing on the affected side, the pelvis will drop on the unaffected side (“the sound side sags”).
🔍 Investigations
- Physical examination tests
- Trendelenburg’s test
- Single leg stance - ask the patient to stand on the affected leg and keep the contralateral knee bent to 90º for 30s. There should be lateral hip pain within the allotted time.
- FABER test - this is flexion, abduction, and external rotation (hence “FABER”) of the hip. It involves placing the lateral malleolus of the affected leg on the patella of the unaffected leg. The knee is passively lowered by the examiner to bring the hip into abduction and external rotation. This should elicit lateral hip pain.
- FADER test - this is flexion, adduction, and external rotation. The hip is passively flexed to 90º with the patient lying supine. The hip is then adducted and externally rotated. It too should elicit lateral hip pain and tests for gluteal tendinopathies.
- Resisted abduction resisted internal rotation and resisted external rotation - should all elicit lateral hip pain.
- 💡 X-ray - should be done to exclude acute fracture, stress fracture or dislocation.
🧰 Management
It is mostly self-limiting and resolves with conservative management. If they do not work we can consider the advanced measures as mentioned above.
Other common sites include:
- Retrocalcaneal bursitis - located between the Achilles tendon and the calcaneum.
- Subacromial bursitis - often occurs with repetitive overhead lifting. It is located between the acromion and the supraspinatus tendon.
- Infrapatellar bursitis - also known as clergyman’s knee. It is located between the skin and tibial tuberosity.
