title: Clinical outcome and microbiological findings using antibiotic-loaded spacers in two-stage revision of prosthetic joint infections.
abstract: OBJECTIVE
  Antibiotic-loaded spacers may improve antimicrobial efficacy in two-stage revision of prosthetic joint infections, but they may also interfere in the course of infection. This prospective study of prosthetic joint infections managed with two-stage revision and antibiotic-loaded spacers (2004-09) analyzes case outcomes and proposes a second-stage culture interpretation scheme.
  
  
  METHODS
  Second-stage infection was diagnosed upon second-stage cultures (synovial membranes, joint fluid, spacers), as either superinfection (≥2 samples, new organism) or persistence (≥1 samples, previously isolated organism). Isolated positive antibiotic-loaded spacers cultures were considered as colonizations.
  
  
  RESULTS
  Of 42 patients, two had two prosthetic infections (n = 44): 25 knees, 19 hips. Spacers contained gentamicin (33), vancomycin (10) and aztreonam (1). Three patients (7%) with wound healing impairment required debridement and spacer exchange. The remainder underwent second-stage surgery as planned: 34 (77%) new arthroplasties, five arthrodeses, one resection arthroplasty and one permanent spacer. Of 18 cases (44%) with ≥1 positive sample, only four (10%) were second-stage infections. Fourteen antibiotic-loaded spacers cultures (34%) were positive. Four new prostheses (9%) supervened further infections: one by the organism isolated in the spacer, three by new bacteria.
  
  
  CONCLUSIONS
  The findings of second-stage cultures show that the surgical site is frequently non-sterile at reimplantation. Isolated positive antibiotic-loaded spacer cultures usually have no clinical consequences, but together with tissue cultures they help to diagnose second-stage infections when clinical signs are absent.
authors: Department of Orthopaedic Surgery, IDIBELL, Hospital Universitari de Bellvitge, Feixa Llarga s/n. 08907, L'Hospitalet de Llobregat, Barcelona, Spain.
authors: Javier
authors: J
authors: Cabo
authors: Gorane
authors: G
authors: Euba
authors: Anna
authors: A
authors: Saborido
authors: María
authors: M
authors: González-Panisello
authors: María Angeles
authors: MA
authors: Domínguez
authors: Jose L
authors: JL
authors: Agulló
authors: Oscar
authors: O
authors: Murillo
authors: Ricard
authors: R
authors: Verdaguer
authors: Javier
authors: J
authors: Ariza