Septic arthritis.

Hematogenous septic arthritis causes pain and effusion and begins with inoculation of the joint with bacteria from the intravascular space. The degradation of ground substance by enzymes released and activated by the acute inflammatory response, toxins and enzymes produced by the bacteria, and T lymphocytes stimulated during the delayed immune response, leads to destruction of the articular cartilage. Whether a given patient will develop a septic joint or a less severe form of infection is dependent upon characteristics of the bacterial strain and of the individual's host defenses. Management consists of systemic antibiotic therapy and decompression of the joint. Synovectomy, salicylate administration, and continuous passive motion are adjuvant therapies that have not as yet not been proved to be of benefit.