Introduction. Currently, against the background of the growth of primary knee arthroplasty, the frequency of revision surgical interventions is increasing. Among all the causes of revision operations, periprosthetic infection occupies one of the leading positions. The generally accepted tactics of two-stage revision, along with the relief of the infectious process, implements other tasks: reducing pain, preserving and/or restoring joint function. Implantable articulating antibacterial spacers allow you to perform all the tasks and maintain/restore the quality of life of patients on stage treatment. However, studies showing the significance of the articulating spacer friction pair are extremely few. The aim of the study was to evaluate the effect of the articulating spacer friction pair on the results of the first stage of treatment of patients with periprosthetic knee joint infection. Material and methods. A single-center, retrospective, cohort study of an open nature was conducted. At the first stage of the study, the results of surgical treatment of 420 patients with periprosthetic knee joint infection treated at the university clinic for the period 2011-2019 were studied. At the second stage, after applying the inclusion and exclusion criteria, 182 patients were included in the analysis. Two representative groups are identified among them. In the comparison group, a hand-made cement insert with an articulating surface was used, in the main group - an official one. Results. Replacement of the cement insert with an official one made of ultra-high molecular weight polyethylene, installation of endoprosthesis components with restoration of anatomical relationships in the joint and the balance of the ligamentous apparatus led to a reduction in the duration of surgery and intraoperative blood loss, a reduction in the duration of hospitalization, an increase in the volume of movements in the joint, greater stability of components and relief of the infectious process in 94.6% of patients. Conclusion. Changes in the technology of surgical treatment have improved the immediate and long-term results of treatment of patients with periprosthetic infection of the knee joint. Key words: knee joint, periprosthetic infection, two-stage revison, articulating spacer.