What is the diagnosis?

Septic olecranon bursitis. The differential diagnosis includes traumatic, septic, and inflammatory (RA, gout, CPPD) olecranon bursitis and may even be caused by overuse. In this case the presence of overlying erythema and subjective fevers makes septic olecranon bursitis more likely.

• Pearl: Up to approximately 50% of all olecranon bursitis cases diagnosed in the emergency department are septic [1]. If septic arthritis is suspected, it must be treated to prevent septic arthritis and sepsis [2].

What is the mechanism of injury?

Traumatic causes include: overuse, direct trauma, and repetitive trauma often related to occupational behaviors [3]. Septic bursitis is caused by infection of the bursa secondary to local infiltration of bacteria through trauma to skin or spread from nearby tissues. 

What physical exam findings are expected?

Olecranon bursitis physical exam findings include well defined, fluctuant posterior elbow swelling which may be painless or painful to palpation and may appear “golf ball” like in appearance [4]. 

Septic bursitis physical exam findings include the above, in addition to tenderness with palpation, erythema and warmth. 

• Pearl: Fever occurs <70% of the time in septic bursitis [5].  

Which diagnostic and imaging modalities can be used?

Olecranon bursitis is typically a clinical diagnosis and does not require imaging. However, plain films can be used to evaluate for olecranon fracture or avulsed osteophyte and will likely show soft tissue swelling superficial to the olecranon. Ultrasound can help differentiate olecranon bursitis from cellulitis and other soft tissue infections (Image 2) [6].  MRI may be used in atypical cases to differentiate bursitis from other diagnoses such as osteomyelitis, stress fracture or triceps tear [7]. 

Image 2. Short axis (left) and long axis (right) of elbow showing olecranon bursitis. Radiopaedia example: Case courtesy of A Abdrabou, Radiopaedia.org, rID: 29196

What is the management in the ED?

Workup in the ED traditionally included bursal aspiration. Findings of aspirate concerning for septic bursitis include cell counts >5000-20,000/uL with predominance of PMNs, positive gram stain, elevated protein, and decreased glucose.

• Pearl: New research shows that aspiration of the olecranon bursa in the ED may be unnecessary even if clinical suspicion for septic bursitis is high. Empiric antibiotics without aspiration appears to safely resolve >90% of cases [8].

Management includes oral antibiotics such as Clindamycin or Bactrim for 14 days and follow up with PCP or orthopedics/sports medicine. A patient may require IV antibiotics and admission if they have extensive purulent bursitis, extensive surrounding cellulitis, concerns for joint involvement, are immunocompromised or have failed a course of PO antibiotics.

When do you consult Orthopedics?

Orthopedics should be consulted for suspected joint involvement or extensive purulent bursitis.