The infection of a total knee replacement often imposes changing implants. The change in two step is currently considered the gold standard. The change in one step is a much debated attitude: strictly contra-indicated for some professionals, but others agree to reserve these for favorable suspected cases selected. Several criteria have been proposed in the literature: age, condition, duration of infection, known bacterium responsible, not virulent and sensitive to antibiotics, no fistula, no significant bone destruction. But these criteria are poorly validated, standing over an experience of surgical teams rather than high-level scientific studies. Some authors have proposed to achieve change in one step systematically. The results of these cohorts on healing the infection does not seem very different from the changes in two steps. But it is most often single-center series, uncontrolled, with small numbers.

Inclusion Criteria:

• Patients over 18 years
• Patient having surgery for the management of knee infection after change in one step of a knee replacement prothesis in the participating services between 2000 and 2010.

Exclusion Criteria:

• Patients under 18 years

Patients over 18 years having surgery for the management of knee infection after change in one step of a knee replacement prothesis in the participating services between 2000 and 2010.