Rationale for choosing a spacer at the first treatment stage for late deep periprosthetic knee joint infection by Stanislav A. Linnik, Anna G. Afinogenova, Gennady E. Afinogenov, Anna A. Spiridonova, Yaroslav B. Tsololo, Giorgi Karagezov, Valerii M. Khaidarov, Dmitry V. Kravtsov, Ivan O. Kucheev, Aleksandr A. Khromov, Ismael Abbas, Maksim V. Maryshev