This study aims to use the technique of microdialysis to analyse the intraarticular space of the hip joint after removal of a periprosthetic joint infection affected endoprosthesis and implantation of an antibiotic-containing cement spacer over the entire period of the first hospitalization (usually 14 days) to closely monitor pharmacological and immunological aspects. In detail, antibiotic concentrations in the joint cavity and systemic circulation will be assessed according to reinfection rates, infection-free survival and fucntional outcome over a 12-month folluw-up period.