Modalités pratiques de prélèvement, de transport et d’analyse d’un liquide synovial en cas de suspicion d’infection

Joint aspiration is the key examination for the diagnosis of septic arthritis. There is no contraindication to performing this procedure if there is a strong suspicion of septic arthritis. It must be carried out before any antibiotic treatment, by the doctor treating the patient for a superficial joint, by the radiologist or surgeon in the case of hip arthritis. Direct examination, cytological analysis, and prolonged bacterial culture on enriched media, are essential to confirm the diagnosis and document the infection. Other investigations (mycobacteria, fungi, etc.), synovial molecular biology techniques or biological markers (alpha-defensin, lactate, etc.) or ultra-sound guided biopsy may be requested in the event of a specific diagnostic orientation or if a first aspiration has remained negative.