Background: Second-stage positive cultures in 2-stage revision arthroplasty are a matter of concern, as their influence in outcomes is not clearly defined. We sought to study reimplantation microbiology when using vancomycin-gentamicin prefabricated cement spacers in hip and knee periprosthetic joint infection. The associations of second-stage positive cultures with treatment failures and patient-associated factors were analyzed.
Methods: We conducted a retrospective cohort study, examining patients managed with 2-stage revision arthroplasty due to knee or hip chronic periprosthetic joint infection between 2010 and 2017. Prefabricated vancomycin-gentamicin cement spacers were used during the spacer stage. Intraoperative microbiological culture results after the first and second stages were evaluated. The primary end point was infection eradication or relapse.
Results: A total of 108 cases were included (61 hips and 47 knees). And 22.2% of patients had ≥1 second-stage positive culture, while 9.3% had ≥2 positive samples. Overall success, at an average follow-up of 46.4 months, was 77.8%. Treatment failure was higher among cases with positive cultures (15.5% vs 45.8%, P < .01) regardless of the number of positive samples. Diabetes was identified as a risk factor for second-stage positive cultures (P = .03); use of cement loaded with extra antibiotics for spacer fixation showed a protective effect (P < .01).
Conclusion: Second-stage positive cultures were related to a higher failure rate when using vancomycin-gentamicin cement spacers. Diabetes increased the likelihood of second-stage positive cultures. The use of extra-antibiotic-loaded cement for spacer fixation during the first stage showed a protective effect.
Keywords: antibiotic-loaded cement; periprosthetic joint infection; second-stage positive cultures; two-stage revision arthroplasty; vancomycin-gentamicin spacers.
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