Septic arthritis: what is it?

L’arthritis septic is a inflammation of one joint (knee, hip, shoulder) generated by an infectious agent. The microorganisms develop in the synovial tissues causing pain and reduced mobility of the joint. Pathology more common in the elderly, it can occur in children in its acute form.

Pathophysiology of septic arthritis

Following penetration into the body (joint injection, surgeryetablishing of prosthesis) or to a diffusion (remote infectious site, bacteraemia), infectious agents multiply in the synovial fluid. Some products from metabolism of these microorganisms increase the inflammatory reaction, and the release ofenzymes by the polynuclear after phagocytosis destroys the synovial membrane. This reaction may continue even after the infection has been treated and may be harmful to the cartilage tissue. The pain and intra-articular effusion encountered in this pathology will be the consequences of these mechanisms.

Different forms of septic arthritis

Clinically, in the context of an acute infection, the distinction is made between gonococcal arthritis (usually in healthy adults) which does not permanently damage the joint and non-gonococcal arthritis, more severe, which damages the cartilage. These are mainly due to Staphylococcus aureus. In 5% of cases, (mycobacteria, fungal infections, bacteria little pathogens), the arthritis can evolve over several weeks, becoming chronic, particularly in patients with risk factor (immunodeficiency, prosthesis, rheumatoid arthritis). Finally, special post-operative care will be provided as part of a arthritis septic on prosthesis, due to the presence of foreign material.

Whatever the form, the diagnostic is based on culture of synovial fluid and treatment antibiotic adapted will be proposed, accompanied by a drainage According to the case.