Cohort of Prosthetic Joint Infections

Inclusion Criteria: * Patient aged over 18 years old with hip, knee and or shoulder joint prosthesis who consented to participate in the study with: * According to musculoskeletal infection society definition: PJI is present when one of the major criteria exists or four out of six minor criteria. Major Criteria: * Two positive periprosthetic cultures with phenotypically identical organisms, OR * A sinus tract communicating with the joint, OR Minor Criteria: * Elevated serum C-reactive protein (CRP) AND erythrocyte sedimentation rate (ESR) * Elevated synovial fluid white blood cell (WBC) * Elevated synovial fluid polymorphonuclear neutrophil percentage (PMN%) * The presence of pus in the joint without known cause * Positive histological analysis of periprosthetic tissue * A single positive culture Or a PJI which meets the following three criteria: * Medical story suggesting prosthetic joint infection. * The presence of pain either with or without swelling for more than 3 months unrelated to a mechanical cause. * Germ identification in a single sample of fluid aspiration or tissue culture. * Or microbial growth in prosthesis sonication fluid culture greater than 50CFU/ml. Exclusion Criteria: * Patient who does not meet eligibility criteria. * Patient lawfully deprived of his liberty. * Patient not insured under social security scheme.