Abstract
Introduction: When treating periprosthetic joint infection with a two-stage procedure, antibiotic-impregnated spacers can be used in the interval between prosthetic removal and reimplantation. In our experience, cultures of sonicated spacers are most often negative. The objective of the study was to assess whether that sonication causes an elution of antibiotics, leading to elevated antibiotic concentrations in the sonication fluid inhibiting bacterial growth and thus causing false-negative cultures.Methods: A prospective monocentric study was performed from September 2014 to March 2016. Inclusion criteria were a two-stage procedure for prosthetic infection and agreement of the patient to participate in the study. Spacers were made of gentamicin-containing cement to which tobramycin and vancomycin were added. Antibiotic concentrations in the sonication fluid were determined by mass-spectometry (LC-MS).Results: 30 patients were identified (15 hip and 14 knee and 1 ankle arthroplasties). No cases of culture positive sonicated spacer fluid were observed in our serie. In the sonication fluid median concentrations of 13.2µg/ml, 392 µg/ml and 16.6 µg/ml were detected for vancomycin, tobramycin and gentamicin, respectively. According to the European Committee on antimicrobial susceptibility testing (EUCAST), these concentrations released from cement spacer during sonication are higher than the minimal inhibitory concentrations (MICs) for most bacteria relevant in prosthetic joint infections.Conclusion:Spacer sonication cultures remained sterile in all of our cases. Elevated concentrations of antibiotics released during sonication could explain partly negative-cultured sonicated spacers. Indeed, the absence of antibiotic free interval during the two-stages can also contribute to false-negative spacers sonicated cultures.
Highlights
When treating periprosthetic joint infection with a two-stage procedure, antibiotic-impregnated spacers can be used in the interval between prosthetic removal and reimplantation
At a mean follow-up of 12.8 months, we had two persistent infections: one patient infected with S. epidermidis and one patient infected with methicilin-resistant S. aureus (MRSA)
Four patients had a re-infection (13.3%): one hematogenous total hip arthroplasty (THA) infection by S. aureus caused by diabetic foot ulcer 9 months later, one hematogenous THA infection by S. aureus 5 months later and two cases of persistent serous discharge of wound 1 month after reimplantation (1 THA infection by E. faecalis and 1 total knee arthroplasty (TKA) infection by E. cloacae)
Summary
When treating periprosthetic joint infection with a two-stage procedure, antibiotic-impregnated spacers can be used in the interval between prosthetic removal and reimplantation. Cultures of sonicated spacers are most often negative. One of the possible options for the treatment of periprosthetic joint infections is a two-stage exchange procedure. During the interval between removal of the prosthesis and reimplantation, antibioticimpregnated cement spacers can be used. They have http://www.jbji.net the advantages of local antibiotic release, dead space management and prevention of soft tissue retraction. Most studies report cases of spacer infection at the second-stage procedure [1,2,3,4]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
