BackgroundThe unsuccessful treatment of prosthetic joint infection (PJI) with two-stage revision leads to infection recurrence. The objectives of the study were to assess the clinical and demographic characteristics of patients with polymicrobial PJI, and to evaluate the role of the microbial profile involved in PJI in the risk of infection recurrence after the first step of two-stage revision surgery.Materials and methodsA retrospective analysis of 189 cases of culture-positive PJI following total hip replacement over a 5-year period was performed. The demographic characteristics of patients, clinical symptoms, microbiology cultures of intraoperative biopsies, laboratory values of C-reactive protein (CRP), white blood cell count and erythrocyte sedimentation rate were analyzed. Patients were divided into two groups—135 with monomicrobial and 54 with polymicrobial infection.ResultsOf all patients, 68.9 % in the monomicrobial and 83.3 % in the polymicrobial group had a body mass index >25 kg/m2 (p = 0.05). The median CRP values were 5.7 mg/L (IQR 4.0–10.0 mg/L) in the monomicrobial compared to 8.8 mg/L (IQR 5.0–27 mg/L) in the polymicrobial group (p = 0.01). The percentage of successful outcomes was 27.8 % in patients with microbial associations (p < 0.0001). Gram-negative pathogens caused polymicrobial PJI in 61.5 % of cases with infection recurrence (OR 4.4; 95 % CI 1.18–16.37; p = 0.03).ConclusionsOverweight and obese patients or those with elevated CRP had a greater risk of polymicrobial PJI. They were predisposed to recurrence of infection after the first step of two-stage revision. An unsuccessful outcome was more likely in cases with polymicrobial infection compared to those with monomicrobial infection. In addition, the presence of multidrug-resistant strains of Gram-negative bacteria substantially increased the risk of PJI treatment being unsuccessful.Level of evidenceLevel III, therapeutic study.

Efficacy of the first step of two-stage revision was 64.1 %. Placement of either articulating or non-articulating spacers did not influence recovery from PJI. Laboratory values of ESR, CRP, BMI and the type of previous surgery were identified as main factors that affect outcomes of the two-stage procedure. A prognostic model with the calculation of a total risk score for PJI recurrence was developed.

The key aspects of the study: 1) what has changed in the structure of revisions in recent years? 2) what is the spectrum of reasons for revision after primary hip arthroplasty and re-revision? 3) what are the demographic features of patients’ population undergoing the revision? Materials and methods. The authors conducted a retrospective evaluation of 2415 hip revision cases during the period of time from 2014 until 2018. Separately the authors assessed revisions after primary surgeries and re-revisions as well as the group of early revisions. Results. In the period from 2014 until 2018 the overall share of revisions was 16,6% from all total hip arthroplasties, at the same time the authors reported the absolute 1.7 times increase in number of revisions as well as increased share of revisions in the total structure of hip arthroplasty from 12,5% to 18,9% without significant variances in the number of primary procedures. The share of early revisions increased from 32.9% in 2013 to 56.7% while the number of early revisions amounted to 37.4% of all primary revisions. Gender composition in primary and revision hip arthroplasty varied insignificantly. Mean age at the moment of hip revision was 59.2% (95% CI from 58.7 to 59.7; Me 60 years) which is slightly less than in primary replacement — 60.2 years (95% CI from 58.9 to 61.1; Me 62 years), but such variances had a high statistical significance, р0.001. The main reasons for primary revisions were aseptic loosening of prosthesis components (50.3%), infection (27.6%), polyethylene wear and osteolysis (9.0%) as well as dislocations (6,2%). Re-revisions structure featured prevalence of infection (69.0%), aseptic loosening (20.8%) and dislocations (7,8%). Mean period of time after primary hip arthroplasty to revision was 7.9 years (95% CI from 7.7 to 8.2; Me 7.3), to first re-revision — 2.9 (95% CI from 2.6 to 3.2; Me 1.2), to second re-revision — 2.2 (95% CI from 1.8 to 2.7; Me 1.1), to third — 2,2 (95% CI from 1.7 to 2.8; Me 1.1), to fourth — 1.0 (95% CI from 0.6 to 1.3; Me 0.6), remaining cases demonstrated rather high heterogeneity. Conclusion. In the result of the present study the authors observed increased number of all revision hip arthroplasties, especially the share of early revisions within first five years from the moment of previous surgery. The most often reason for revision after primary hip arthroplasty was aseptic loosening of one or both components of prosthesis. Infection was the absolute leader in the group of re-revisions constituting over half of all reasons for secondary intervention.

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