Recurrent knee pyarthrosis with intact hyaline cartilage. A case report.

A 20-year-old patient with hyperimmunoglobulin E and abnormal leukocyte chemotaxis was treated by synovectomy for chronic and recurrent staphylococcal knee pyarthrosis. The articular cartilage was noted to be preserved despite the severity of synovial involvement and the chronic nature of this case of septic arthritis. Polymorphonuclear leukocytes were few, despite florid Staphylococcus aureus growth. This observation lends support to the role of lysozomal enzyme activity from leukocytes in hyaline cartilage damage in pyarthrosis.