Olecranon Bursitis Work-Up
Obtain plain radiographs of the elbow as the initial imaging study to exclude fractures, dislocations, or bony abnormalities, then aspirate the bursa under ultrasound guidance and send fluid for cell count with differential, Gram stain, culture with sensitivities, and crystal analysis. 1, 2
Initial Imaging
Radiographs are the recommended first-line imaging modality to rule out underlying osseous pathology including fractures, olecranon spurs, or other bony abnormalities that may contribute to or complicate bursitis 1
Ultrasound serves dual purposes: it confirms the diagnosis by demonstrating bursal fluid collection and guides accurate aspiration of the bursa 2, 3
Ultrasound findings in olecranon bursitis include bursal thickening, heterogeneous echogenicity in chronic cases, and allows measurement of bursal volume 1, 3
Ultrasound can detect additional pathology including synovial proliferation, loose bodies, calcifications, rheumatoid nodules, gout tophi, and increased blood flow suggesting inflammation 3
Bursal Fluid Analysis
The critical step in distinguishing septic from aseptic bursitis is comprehensive bursal fluid analysis 2:
Cell count with differential to assess for inflammatory versus infectious etiology 2
Gram stain and culture with sensitivity testing to identify bacterial pathogens and guide antibiotic selection 2
Crystal analysis when crystal arthropathy (gout or pseudogout) is suspected as the underlying cause 2
Clinical Context for Interpretation
Physical examination findings overlap significantly between septic and aseptic bursitis, making fluid analysis essential 4:
Tenderness occurs in 88% of septic cases versus 36% of aseptic cases 4
Erythema/cellulitis appears in 83% of septic cases versus 27% of aseptic cases 4
Warmth is present in 84% of septic cases versus 56% of aseptic cases 4
Fever occurs in 38% of septic cases but is absent in aseptic cases 4
History of trauma or skin lesions is found in 50% of septic cases versus 25% of aseptic cases 4
Additional Evaluation
In patients with inflammatory arthritis, evaluate for systemic disease involvement as olecranon bursitis may represent a manifestation of rheumatoid arthritis or other systemic conditions 1
Consider occupational or athletic history, as repetitive submaximal stress (particularly in javelin throwers and baseball pitchers) predisposes to olecranon pathology including spur formation 1
Common Pitfalls
The most critical error is treating suspected septic bursitis with antibiotics alone without drainage—septic olecranon bursitis requires drainage as primary treatment, particularly when purulent collections and surrounding inflammation are present 1. Relying solely on clinical examination to distinguish septic from aseptic bursitis is unreliable given the significant overlap in physical findings 4.