Olecranon Bursitis - Student's Elbow

The olecranon bursa lies over the ulna at the posterior tip of the elbow. Since it is so near the surface it is frequently subject to trauma. Typically this is caused by constant irritation when the patient leans on the table whilst reading or writing but can also be caused by a fall onto a hard surface.¹

Non-septic olecranon bursitis is a common condition. The exact incidence is unknown as most cases are treated in the community. More information is available from hospital statistics about septic arthritis. One Canadian study based on 118 cases projected a minimum population annual incidence of 10/100,000. The mean age was 44 years and males predominated (88%).²

History

The principle symptoms are focal swelling overlying the posterior tip of the elbow, which may or may not be painless. Pain tends to lessen with the chronicity of the condition. The pain is often exacerbated by pressure, such as leaning on a table.

Clues about aetiology may be evident from the history. Onset may date from an isolated episode of trauma resulting in a contusion or occupation or activity may cause recurrent microtrauma (e.g. carpet laying or writing at a table). Acute onset without trauma is suggestive of infection.

In the Canadian study of septic bursitis, 53% of cases had preceding injury. Symptoms in order of frequency were pain, redness, fever and chills.²

Examination¹

A clearly demarcated swelling in the region of the posterior elbow tip is the classic finding. It has been described as having the appearance of a 'goose egg'. The area may be tender to palpitation with redness and warmth, particularly if infection is present. Skin inspection may reveal contusion or abrasion if there was recent injury.

A difference in temperature of 2.2 degrees C between the affected side and the normal side measured by a surface temperature probe is a significant pointer to infection.³

The range of movement of the joint is usually normal but may be limited at the end of flexion due to pain. Unusual restriction of active or passive movement with a history of trauma raises the suspicion of fracture of the olecranon process.

Systemic symptoms are not usually present unless the infection is advanced, in which case there may be a fever.

Other joints should be examined for signs of crystal arthropathy or of systemic inflammatory processes such as rheumatoid arthritis (e.g. rheumatic nodules).

Elbow pain during active or passive movement may increase the clinician's suspicion of fracture of the olecranon process if there is a history of trauma.

The differential diagnoses can include fracture of the olecranon process, haemarthrosis,⁴ inflammatory arthropathy,⁵ crystal arthropathy,⁶ auto-immune disease,⁷ Ehlers-Danlos Syndrome and synovial cyst. The most significant diagnostic decision is whether sepsis is present or absent.¹

The diagnosis is usually made clinically but the following may be appropriate if an underlying disease process is suspected or in cases of diagnostic difficulty.

Laboratory studies

A raised white cell count will suggest infection. Check uric acid levels, rheumatoid factor, the erythrocyte sedimentation rate and the C-reactive protein level.¹

Imaging studies

If there is a history of significant trauma, a plain X-ray should be arranged to exclude fracture of the olecranon process.

Ultrasound may be helpful, particularly in the early stages. It may detect effusions, synovial proliferation, calcifications, loose bodies, rheumatoid nodules, gout tophi and septic processes.⁸

Rarely, MRI may be needed to exclude osteomyelitis or abscess formation.⁹

Procedures

Aspiration of the bursa is useful both for diagnostic purposes and to relieve symptoms. An 18 gauge needle should be used, and a zig-zag technique employed to minimise the risk of fistula formation.

If redness, fever, previous puncture wounds or cellulitis suggests infection, send the fluid for microscopy and culture.¹⁰ Some studies state that a leukocyte count of 2,000 -100,000 suggests inflammation, whilst a count above 100,000/mL suggests infection.¹ Gram staining, culture and sensitivity will help to identify any infective agent and help to guide treatment.

The presence of crystals will suggest a crystal arthropathy. Monosodium urate crystals are characteristic of gout, calcium pyrophosphate or hydroxyapatite crystals are characteristic of pseudogout.¹⁰

Rheumatoid arthritis,⁵ gout,¹ tuberculosis,¹¹ Mycobacterium szulgai infection,¹² HIV,¹³ chronic renal disease (may be due to uraemia or repeated microtrauma during dialysis),¹⁴ plus any condition that compromises the immune system (e.g. alcohol, steroids,¹⁵ diabetes,¹).

Physical therapy

There is a lack of a large evidence base, but structured exercises appear to be of benefit in non-septic bursitis.⁷ The RICE method (Rest, Ice, Compression, Elevation) is also advocated.¹ Phonophoresis (the use of ultrasound to increase the absorption of topically applied drugs¹⁶) and electrical stimulation are also occasionally used to reduce pain and inflammation.¹⁰

Medical treatment

Septic bursitis should be treated with antibiotics based on the results of microbiology tests. Most infections are due to Staphylococcus aureus,² although other organisms can occur.¹⁷ If antibiotics have to be given empirically before the results of cultures are known, a penicillinase-resistant penicillin should be started such as flucloxacillin.¹⁸ A cefalosporin such as cefuroxime can be used in cases of penicillin-allergy.¹⁸ Antibiotics may be given orally, facilitating ambulatory treatment. However, if symptoms are particularly severe, the parenteral route may be required initially.²

Non-steroidal anti-inflammatories can be of value in non-septic bursitis but may be less effective than corticosteroid injection.¹⁹

Surgical procedures

Aspiration of the bursa followed by immediate instillation of corticosteroid may be used for the acute relief of inflammation but should be avoided if there is any suspicion of infection.¹⁰ Patients should be counselled as to the complications, which can include swelling, infection and persistent drainage through the injection track. Ulnar nerve injury can occur if the median approach is used.¹ A compressive elbow sleeve may help prevent the reaccumulation of bursal fluid after aspiration.¹

More interventional procedures are rarely needed. Drainage is occasionally required,² with removal of the bursa (bursectomy) being reserved for cases resistant to other treatment. Endoscopic removal of the bursa sac achieves good results.²⁰

Septicaemia and osteomyelitis can occur in severe septic bursitis, particularly if the condition presents late or the diagnosis is not immediately obvious.²¹ Persistent pain and associated decreased functional use may be caused by the disease process in recalcitrant cases.¹

Most patients respond well to treatment unless there is persistent infection.^1,21 Corticosteroid injection is usually effective in non-septic bursitis, and long-term sequelae are unusual.²²

Patients should be advised to avoid excessive pressure over the elbow. Care should also be taken not to traumatise the elbow from persistent rubbing or contact sports. Elbow pads may help to prevent recurrence until the initial inflammation resolves.¹