Importance of the Algorithm for Diagnosis of Late Deep Periprosthetic Hip Infection

Abstract
Relevance. Late deep periprosthetic infection (PJI) of the hip joint is a serious complication after arthroplasty which takes the lead among the world reasons for revision. Accurate diagnostics allows to achieve good results and select a proper treatment tactics. Purpose of the study - to evaluate the efficiency of diagnostics algorithm for late deep PJI and impact of the microbial landscape on the risk of infection recurrence. Materials and methods. The authors evaluated two groups of patients who underwent revision in the period from 2002 to 2014 and from 2015 to 2018. The first (retrospective) group included 144 patients who were not diagnosed for late deep PJI. The second (prospective) group included 157 patients who underwent detailed diagnostics for late deep PJI based on the algorithm including the analysis of X-rays, pelvic CT, triple evaluation of ESR and CRP, puncturing of affected joint and microbiology examination. The authors assessed the microbial landscape in 51 patients with late deep hip PP. Results. In the first group 12 patients (8.3%) underwent sanation and spacer insertion during first stage of treatment, 46 patients (59.7%) after revision demonstrated positive intraoperative cultures confirming septic etiology of implant loosening, 19 patients (24.67%) had no flora growth, and no intraoperative microbiological examination was done for remaining 67 patients (46.52%). In the second group after detailed diagnostics 51 patients (32.4%) underwent removal of prosthesis and spacer insertion in the first stage, other 13 patients (8.2%) featured flora growth after revision, remaining 93 patients (59.2%) had no flora growth after revision. Recurrent PJI was observed in 21 patients (14.5%) in the first group, and in 10 patients (6.3%) in the second group. In the second group recurrent PJI was reported in 40% of patients due to microbial associations, in 30% - due to MRSA, in 20% - due to culture negative bacteria and in 10% - due to S. aureus. Conclusion. Triple examination allows to obtain an accurate diagnosis and isolate the pathogen for deep PJI. Application of such diagnostics algorithm allows to reduce 2.1 times the risk of recurrent deep PJI and to scale down 4 times the detection of type IV infection by Coventry-Tsukayama classification.