Idiopathic or traumatic olecranon bursitis. Clinical features and bursal fluid analysis.

Thirty cases of idiopathic olecranon bursitis were studied. Most had previous local trauma. The process was unilateral and often associated with nontender pitting edema in cases of short duration. Ten patients exhibited a bony spur at the olecranon process, and amorphous calcific deposits were seen in 6. The bursal fluid was hemorrhagic with a xanthochromic supernatant, and the mucin clot test was poor or fair. Leukocyte count averaged 878/mm3, predominantly mononuclears. Many cells contained inclusion bodies. Glucose, total protein, and complement (C3) concentration averaged 80, 60, and 60% of the respective serum values.