Spacers in two-stage strategy for periprosthetic infection.

In two-stage revision of infected implants, the first stage involves removing the implant and implanting a joint spacer, and the second stage involves implanting a new prosthesis at least 6 weeks later. Spacers have two main functions: local administration of high-dose antibiotics, and preservation of the joint space by reducing soft tissue retraction and improving patient comfort until reimplantation. The present review aims to detail the necessary characteristics of antibiotics added to cement to achieve good joint diffusion, to describe the steps of two-stage revision, and to present the types of spacer available according to the joint and complications. The antibiotic used in the spacer must be heat-resistant, water-soluble and chemically stable in the cement. Gentamicin and vancomycin are generally preferred. We recommend at least 3 months' systematic antibiotic therapy for periprosthetic joint infection. Reimplantation is performed either at 6 weeks without antibiotic washout or 3 months after 2 weeks' washout Spacers may be static (non-articulating) or dynamic (articulating). Static spacers are mainly used in the knee or hip in cases of severe bone defect or risk of soft-tissue lesions. An articulating spacer enables some joint functions to be preserved in the knee, hip or shoulder. The most frequent complications are the dislocation of dynamic spacers and the breakage of static or dynamic spacers. To optimize efficacy and minimize complications, the biomechanical and bacteriological characteristics of spacers must be considered. LEVEL OF EVIDENCE: Expert opinion.