01OverviewDefinition, clinical context and the essential points that orientate the chapter.
The olecranon bursa lies just beneath thin posterior elbow skin, allowing easy inspection and palpation but also exposure to pressure and skin inoculation. Ask about leaning habits, occupation, recent fall, abrasion, gardening, bite, injection, previous episodes and antimicrobial use. Establish gout, rheumatoid arthritis, diabetes, immune suppression, kidney disease, anticoagulation and systemic symptoms. A patient who can flex and extend reasonably can still have a septic bursa; preserved movement separates it imperfectly from joint sepsis and never makes infection harmless.
Inspect size, colour, skin break, punctum, drainage and proximal or distal spread. Palpate temperature, fluctuance, solid nodules and bony tenderness without squeezing contaminated fluid through tissue. Mark the erythema and document elbow range, active extension, distal neurovascular status and regional lymph nodes. Severe pain with passive joint movement or an intra-articular effusion requires a septic-arthritis pathway. Loss of active extension after trauma raises fracture or triceps disruption.
Typical small sterile swelling after repeated pressure can be managed clinically. Obtain radiographs for trauma, suspected spur, foreign body, calcification or chronic atypical disease. Ultrasound distinguishes fluid from solid mass and can locate collections when examination is uncertain. If septic or crystal bursitis is plausible, aspirate aseptically through healthy skin when this can be done safely and promptly. Send appearance, cell count if available, Gram stain, bacterial culture and crystal analysis; crystals and infection can coexist.
For non-septic disease, remove the cause: avoid direct pressure, use an elbow pad, change desk or vehicle position, and protect skin. Compression may limit reaccumulation if neurovascularly comfortable, while ice and a brief topical or oral analgesic course can help. Do not immobilise the elbow for long because stiffness develops. Traumatic haemorrhagic collections usually settle, but anticoagulation indication and bleeding severity need clinician review rather than unilateral medicine cessation.
Septic bursitis most often requires antistaphylococcal therapy and close review. A stable patient without deep infection may receive an oral regimen consistent with local antimicrobial policy after a sample, whereas systemic illness, rapid spread, immune compromise or oral-treatment failure requires hospital assessment, intravenous treatment and surgical evaluation. Drainage may be repeated or performed surgically for loculation, abscess, necrotic skin or persistent infection. Culture results must narrow or redirect therapy.
Corticosteroid injection is not routine. Sterile aspiration alone may be considered for a very tense, painful or diagnostically uncertain collection, but reaccumulation is common and every puncture adds infection risk. Steroid may shorten symptoms in selected confirmed non-infected disease yet can thin the superficial skin, depigment it and seed infection. Never inject through cellulitis, into suspected bacterial bursitis or without a clear benefit that outweighs the risk.
Recurrent bursitis prompts a cause review: repeated pressure, retained foreign body, spur, gout, rheumatoid disease, persistent infection or an alternative mass. Treat crystal disease according to the underlying diagnosis after infection exclusion. Chronic draining sinus, recurrent culture-positive disease, repeatedly disabling sterile swelling or threatened skin may lead to bursectomy. Discuss wound-healing problems because posterior elbow skin is vulnerable and avoid promising that surgery prevents recurrence if pressure continues.
Pregnancy mainly changes analgesic and antibiotic selection rather than diagnostic urgency; infection still requires prompt treatment. Older adults and people with diabetes or immune suppression can deteriorate with muted fever, so use a lower threshold for acute review. Renal disease affects both gout interpretation and antimicrobial or NSAID dosing. Anticoagulation increases haemorrhagic swelling and procedural bleeding; coordinate aspiration or surgery without unsupervised interruption.
Key points
- Olecranon bursitis produces a discrete fluctuant swelling directly over the posterior elbow; passive joint movement is often relatively comfortable unless the bursa is tense or the joint is involved.
- Always separate septic from non-septic disease using warmth, erythema, skin breach, drainage, fever, immune risk and pain with passive joint movement.
- First-line investigation for uncomplicated pressure-related swelling is clinical assessment; routine aspiration is unnecessary and can introduce infection.
- Aspirate when infection or crystal disease is a meaningful possibility and the result will change treatment, using aseptic technique away from cellulitic skin and sending cell count, Gram stain, culture and crystals.
- First-line sterile management is pressure avoidance, padding, compression when comfortable, ice and short suitable analgesia; preserve elbow movement.
- Suspected septic bursitis requires prompt anti-staphylococcal antibiotics after sampling when safe, early review and escalation for systemic illness, abscess, deep extension or failure.
- Do not inject corticosteroid into a hot, infected or unconfirmed bursa; routine steroid use is limited by skin atrophy, infection and recurrence risk.
- Consider bursectomy or treatment of an olecranon spur only for recurrent, chronic, draining or treatment-resistant disease after the cause has been reviewed.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Repeated pressure
Leaning the posterior elbow on a desk, vehicle surface or tool repeatedly irritates the superficial bursa and causes sterile fluid accumulation.
Direct trauma
A blow or fall can produce haemorrhagic swelling, with larger collections in people taking anticoagulants or with a bleeding disorder.
Crystal and inflammatory disease
Gout, calcium pyrophosphate deposition and rheumatoid disease can inflame the bursa or create nodular material around it.
Bacterial inoculation
Staphylococcus aureus commonly enters through an abrasion, puncture or inflamed skin; diabetes, immune compromise and repeated aspiration increase susceptibility.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Superficial friction response
The normally thin bursal sac produces excess fluid when repeated shear and compression irritate its synovial lining.
- 2Haemorrhagic expansion
Trauma can rupture small vessels into the bursa, causing rapid bruised swelling while the elbow joint itself may retain movement.
- 3Crystal inflammation
Urate or calcium pyrophosphate crystals activate innate inflammatory pathways and can coexist with bacterial infection, so finding crystals does not exclude culture-positive disease.
- 4Septic propagation
A superficial portal permits bacterial proliferation within fluid, followed by cellulitis, loculation, sinus formation or extension into deeper tissue and bloodstream.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
A well-defined soft swelling directly over the olecranon identifies the superficial bursal compartment rather than a diffuse intra-articular effusion.
Warmth, erythema, tenderness, a skin portal, purulent fluid or systemic illness increases infection probability and demands early treatment.
Isolated bursitis often allows flexion and extension, whereas severe pain throughout passive movement raises concern for septic arthritis or fracture.
Gradual swelling after repeated leaning, with little warmth and intact skin, supports aseptic microtraumatic bursitis.
Recurrent abrupt inflammation, tophi or known gout suggests crystals, but aspirated fluid still requires microbiology when sepsis is plausible.
Bruising, bony tenderness or inability to extend actively should redirect assessment to olecranon fracture or triceps injury.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
First-line clinical compartment assessmentFirst stepFirst line - Why
- Distinguish bursal swelling from joint effusion, fracture, tendon rupture, cellulitis and solid mass.
- Interpretation and limitations
- A discrete posterior sac with usable passive movement supports bursitis; systemic signs or marked joint pain require urgent escalation.
- 02
Bursal aspiration when infection or crystals matter - Why
- Obtain diagnostic fluid before antimicrobials when this is safe and will not delay unstable-patient treatment.
- Interpretation and limitations
- Send Gram stain, culture, cell count and crystals; cloudy fluid supports infection but appearance and cell count alone are not definitive.
- 03
Blood tests for systemic disease - Why
- Assess FBC, CRP, renal function, glucose and blood cultures when infection severity or comorbidity warrants them.
- Interpretation and limitations
- Markers help trend systemic inflammation but normal values cannot exclude local bacterial infection, especially early or in immune compromise.
- 04
Plain elbow radiographs - Why
- Identify fracture, olecranon spur, foreign body, calcification or destructive bone disease.
- Interpretation and limitations
- Radiographs are not required for every atraumatic sterile swelling; gas, erosion or fracture changes urgency and specialist involvement.
- 05
Ultrasound for uncertain anatomy - Why
- Confirm fluid, loculation, abscess or solid lesion and assist safe aspiration when landmarks are unclear.
- Interpretation and limitations
- Imaging must not delay antibiotics and source control in a clinically septic patient and cannot replace culture.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Septic arthritis
Joint infection causes much greater pain with passive flexion and extension and often an effusion centred within the joint rather than a discrete posterior sac.
Gouty tophus or flare
Firm chalky material, recurrent episodic inflammation and hyperuricaemia history support gout, but aspiration must still include culture when infection is possible.
Olecranon fracture
Trauma, bony tenderness, bruising and loss of active extension require radiographs; swelling may obscure a displaced fracture or triceps disruption.
Rheumatoid nodule
A firm usually non-fluctuant lesion in established seropositive disease differs from an acute fluid-filled bursa but may ulcerate or become infected.
Soft-tissue tumour
A persistent solid, enlarging or atypically painful mass that does not follow pressure or inflammation warrants ultrasound or tumour-pathway imaging.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01First-line sterileProtect the bursa and preserve movementFirst stepFirst linePressure-related posterior swelling is minimally inflamed, skin is intact and infection or fracture is unlikely.+
- 1Identify and remove the direct pressure source and provide a properly fitted elbow pad or workplace adjustment.
- 2Use ice, comfortable compression and the safest short analgesic option while continuing gentle elbow movement.
- 3Avoid routine aspiration because fluid often reaccumulates and puncture can introduce infection.
- 4Review if warmth, erythema, fever, drainage, rapid enlargement or impaired joint movement develops.
02Diagnostic aspirationSample a potentially septic bursaWarmth, erythema, portal of entry, immune risk or crystal features make fluid analysis clinically important.+
- 1Assess sepsis and joint involvement first, marking erythema and documenting distal function.
- 2Using aseptic technique, enter through healthy skin rather than cellulitis and collect enough fluid for culture and crystal analysis.
- 3Start prompt empiric treatment after sampling when bacterial infection is suspected, without delaying therapy in systemic illness.
- 4Review within 24 to 48 hours or sooner if worse and tailor treatment to culture, renal function and clinical response.
03Urgent infectionEscalate systemic or deep spreadEscalationThe patient is systemically unwell, infection spreads rapidly, immunity is impaired, oral treatment fails or abscess and joint involvement are possible.+
- 1Use an acute sepsis assessment, obtain blood cultures when indicated and start local intravenous antimicrobial therapy promptly.
- 2Seek same-day orthopaedic assessment for drainage, deep sampling and exclusion of septic arthritis or osteomyelitis.
- 3Elevate and protect the limb while maintaining neurovascular observation and marking spread.
- 4Narrow therapy when cultures return and plan wound and recurrence follow-up after source control.
04RecurrentFind the driver before surgerySwelling repeatedly returns, a sinus develops or reasonable conservative and infection treatment has failed.+
- 1AlternativeReassess pressure exposure, skin disease, foreign body, spur, gout, rheumatoid disease and alternative mass.
- 2Use radiographs or ultrasound selectively and repeat microbiology for recurrent inflammatory or draining disease.
- 3Refer for bursectomy or spur treatment when recurrent disability, chronic infection or threatened skin justifies wound risk.
- 4Continue pressure avoidance after intervention because surgery does not remove the original mechanical exposure.
Key medicines and prescribing safety3 treatments · regimens, roles and cautions+
Topical diclofenac for confirmed sterile pain
On intact elbow skin, spread 2–4 g of diclofenac 1.16% gel per dose, using no more than three or four doses daily for a short course and observing the licensed maximum.Do not apply to broken, infected or draining skin, avoid NSAID hypersensitivity and combined excess NSAID exposure, and follow pregnancy restrictions including avoidance in the third trimester.
Oral flucloxacillin for selected stable septic bursitis
When local antimicrobial guidance supports outpatient treatment, use flucloxacillin 500 mg to 1 g orally four times daily on an empty stomach, commonly for 7 days initially, then review early and extend or change according to culture, depth and response.Immediate hospital care and intravenous therapy are required for systemic illness or deep spread; avoid in severe penicillin allergy, review hepatic and renal history, interactions and pregnancy, and act on culture results.
Corticosteroid injection only in selected aseptic disease
If specialist or trained primary-care assessment confirms non-infected recurrent inflammatory bursitis, use one small intrabursal dose under the local protocol after aspiration; do not prescribe a routine repeat series.Never inject suspected infection or through damaged skin; discuss superficial skin atrophy, depigmentation, bleeding, hyperglycaemia and iatrogenic infection, with extra caution because the bursa is immediately subcutaneous.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Cellulitis and sepsis
Untreated bacterial infection can spread through superficial tissue, enter blood and cause systemic deterioration, particularly in diabetes or immune compromise.
Chronic draining sinus
Recurrent infection, skin compromise or repeated procedures may leave a persistent tract that requires culture-directed treatment and surgical assessment.
Recurrent sterile swelling
Continued pressure, an untreated spur, crystal disease or an unmodified occupation can cause repeated fluid accumulation after initial improvement.
Procedure-related infection
Aspiration and steroid injection can introduce bacteria; injections through inflamed skin or before infection exclusion create avoidable harm.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- For suspected infection, review temperature, erythema margin, pain, swelling, joint movement and systemic observations within 24 to 48 hours.
- Check culture and susceptibility promptly and narrow, extend or redirect antimicrobials according to depth and response.
- Monitor renal and hepatic factors, allergy, drug interactions and diarrhoea during antibiotic treatment.
- For sterile bursitis, track recurrence against pressure avoidance and padding rather than repeatedly measuring fluid alone.
- After aspiration or injection, provide immediate return advice for increasing pain, redness, fever, drainage or neurological symptoms.
- Reassess chronic or solid swelling for gout, rheumatoid disease, foreign body, spur or tumour before assuming simple recurrence.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Movement does not clear infection
A septic superficial bursa may coexist with relatively comfortable elbow motion; preserved movement mainly makes intra-articular infection less likely, not bacterial bursitis impossible.
Crystals and bacteria coexist
Finding urate or calcium pyrophosphate does not end the microbiology work-up when skin breach, fever or purulence raises sepsis concern.
Routine aspiration has a cost
Many pressure-related collections reaccumulate, and every needle pass through thin posterior skin creates a route for infection.
The portal may be tiny
A small gardening scratch or fissure can seed Staphylococcus aureus into the bursa, particularly in diabetes or immune compromise.
Joint pain changes the target
Severe restriction throughout passive movement should prompt joint aspiration and orthopaedic management, not repeated bursal treatment alone.
Pressure modification prevents recurrence
Padding and workspace change address the mechanical driver; drainage or surgery without these measures leaves exposure unchanged.
11Common pitfallsFrequent interpretation and management errors.
- 01
Reassuring a hot bursa because the patient can still flex and extend the elbow.
- 02
Aspirating every painless pressure swelling and thereby introducing infection into a superficial sac.
- 03
Failing to send both microbiology and crystals when infection and gout are plausible.
- 04
Injecting corticosteroid through cellulitic or damaged skin or before bacterial disease is excluded.
- 05
Stopping anticoagulation without responsible clinical review in a patient with traumatic haemorrhagic swelling.
- 06
Treating recurrent swelling without addressing leaning pressure, skin portals, gout, rheumatoid disease or an olecranon spur.