Olecranon Bursa Aspiration

Anatomy and Physiology

The olecranon bursa is a fibrous sac that lies between the point of the elbow, the olecranon, and the skin.[2] It is adherent to both surfaces. The bursal lining secretes an oily substance called hyaluronic acid, a principal component of synovial fluid. This substance has a very low coefficient of friction. Thus, it permits the skin and elbow to slide dependently from each other, preventing the olecranon process from protruding through the skin. This is a vital function for quality of life.

In the normal state, the olecranon bursa does not communicate with the elbow joint cavity.

When patients become symptomatic from irritation of the olecranon bursa, the bursa will react by swelling and increasing the secretion of hyaluronic acid and other substances depending on the cause. Thus, precision in diagnosis is fundamental to proper treatment.[3]

Indications

When the olecranon bursa is inflamed and tender, interfering with the patient's ability to lean on their elbows, drainage of the bursa is important to determine etiology. Treatment will depend upon precise etiology.[4]

Even though the patient may have had a prior episode of olecranon bursitis, the current episode, unless precisely stereotypical of prior events, does not diagnose the current episode. In other words, having had previous traumatic olecranon bursitis in no way rules out a current infectious etiology.

The prime indications and purposes for drainage of an olecranon bursa are:[5]

1. Diagnostic evaluation
2. Symptomatic relief
3. Therapeutic intervention

Contraindications

The olecranon bursa is sterile at baseline. It is imperative not to introduce infection. Thus, performing an aspiration through an infected site (cellulitis) is an absolute contraindication.[6] The operator must find a way to introduce a needle into the bursa without seeding the bursa with bacteria from an overlying infection. If the infection of the bursa itself is suspected, however, aspiration is absolutely indicated.[7]

Additionally, a trauma that disrupts the periosteum is an absolute contraindication to aspiration because of the risk of introducing infection. Thus, tapping the olecranon bursa in the setting of olecranon fracture is not to be done.

Equipment

1. Syringe for aspiration, 3 to 5 cc preferred, depending on estimates of fluid quantity.[4]
2. A needle of sufficient gauge to aspirate a viscous fluid; 18-gauge 1.5 inches recommended.
3. An antiseptic solution such as chlorhexidine or betadine for skin cleansing.
4. (Optional) Suitable anesthetic, preferably topical, so as to not introduce a complicating factor. Consider ethyl chloride.[8]
5. Suitable personal protection equipment (gloves, clean, non-sterile generally acceptable with attention to detail)

Personnel

Suitably trained personnel are a must. This is a procedure that can be taught to medical students, but supervision should be provided until the trainee is trustable.[5][4]

Preparation

Be certain to inform the patient of the impending procedure, including harms versus benefits, purposes, alternatives. Obtain their informed consent.

Consider utilizing point of care ultrasound if there is a question about overlying cellulitis or the presence/quantity of fluid in the bursa.[9]

1. Cleanse the skin with an antiseptic solution as above.
2. If anesthesia is to be used, ethyl chloride can be sprayed in the skin or a small amount of lidocaine or similar agent injected in a small subcutaneous wheal. If an injected anesthetic is used, be certain not to enter the bursa as this will alter the results of testing requested.

Technique or Treatment

Proper technique is imperative. The underlying anatomy must be kept in mind. The aspirating needle should enter the bursa parallel to the ulna. In general, the posterior approach is most common, but an anterior approach may be used, staying in line with the ulna. Occasionally, an approach from medial or lateral to the bursa maybe use, but this approach risks striking the underlying olecranon, injuring the periosteum. In the event of infection, this could raise the risk of osteomyelitis, although this is rare.

Once the aspirating needle is inserted into the bursa, general traction is applied to the plunger.

When the bursa is decompressed, the needle is removed, and a sterile dressing is applied. Consider adding a compression bandage over the sterile dressing.

In general, unless the final diagnosis of the bursitis is known, medications are rarely injected into the bursa.

The installation of steroids makes little difference to irritative causes of bursitis except for uric acid.[10]

Antibiotics are generally not injected into the bursa. If the bursa is suspected of being infected, it should be irrigated.[11]

Sclerosis of the bursa is to be discouraged as this would erase its purpose, lubricating and cushioning.[6]

Complications

Complications are rare with a proper aspiration of the olecranon bursa; introducing infection into a previous sterile bursa is the most common. Occasionally, because of trauma, blood can be introduced into the bursa when it was not present theretofore; this will resolve on its own.

Occasionally, the bursa does not have fluid in it. For this reason, point of care ultrasound can be useful prior to the aspiration to ensure there is a fluid pocket to aspirate.[6][9]

Clinical Significance

Olecranon bursa aspiration will almost always be for diagnostic purposes.  The tests ordered depends on the etiology suspected.  If there is a question of cystic versus solid, point-of-care ultrasound is a mandatory procedure. 

The primary or common diagnoses are trauma, infection, and degenerative.[1]

Rare causes are neoplastic, foreign body, primary and inflammatory disease (rheumatoid arthritis, psoriatic arthritis, spondylitis). If the cause of the olecranon bursal effusion is uncertain, proper laboratory analysis is imperative.

Tests to consider:

• Cell count with differential
• Gram stain
• Viscosity assessment
• Culture, aerobic (Staphylococcus is most common; anaerobic infections are fulminant and extremely rare)
• Culture, tubercular (depend on setting and chronicity)
• Culture, fungal (depending on presentation and immune status)
• Crystal analysis (consider in the setting of gout, pseudogout)
• Inflammatory causes: antinuclear antibody (ANA), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP)[4]

Findings by etiology:

• Infectious: (+) Gram stain, WBC/RBC ratio greater than peripheral (often greater than 50 k/mm3)
• Trauma: elevated RBC with an RBC to WBC ratio consistent with peripheral blood
• Degenerative: may have an elevated BBC without infectious etiology.
• Crystal arthropathy: crystal microscopy will be positive for crystals specific for the disease.
• Rare infection (TB, fungal): may require special culture media with a high index of suspicion.
• Autoimmune/inflammatory diseases: frequently elevated WBC with positive testing specific for the disease state.

Inflammatory and infectious etiologies will frequently cause a decrease in bursa fluid viscosity and an increase in turbidity.  The fluid will go from being clear and fairly viscous, with a customary "string sign" to cloudy with a thin, watery consistency on bedside evaluation.  This can be assessed by observing the movement of the aspirate in the barrel of the syringe with a small amount of air.  It can also be observed by pressing a small amount of fluid out of the end of the syringe and observing a drop of fluid dripping toward the surface below.  Normal fluid is viscous and has a tenuous strain that appears to be mucoid.  The abnormal fluid will be thin, dripping like water

Enhancing Healthcare Team Outcomes

Clear communication with the laboratory regarding suspected etiologies is important.  Many locations may require tests to be sent to outside labs.  Consultation with an available pathologist will be helpful.

Nursing, Allied Health, and Interprofessional Team Interventions

The nursing staff has a special skill in patient education.  It is useful to have nursing staff educate the patient about the proposed procedure and counsel on test results and therapies.

Nursing staff should also prepare a sterile tray: topical antiseptic, 18-gauge needle, 5 to 10 cc syringe for aspiration, 1 to 3 cc syringe if an injectable anesthetic is chosen. Clean dressing materials and compression dressing such as Coban

Anesthetic options: ethyl chloride spray or lignocaine 2.5% and prilocaine 2.5% cream for skin anesthesia; injectable lidocaine (with or without epinephrine) may be used if desired by the patient.[12]  

Nursing, Allied Health, and Interprofessional Team Monitoring

Observation of the patient for signs of vasovagal response[13] to the administration of anesthetic or presentation of needle

Additionally, if therapies are administered to the patient at this point of contact, observation for adverse reactions by nursing staff is mandatory.