title: Percutaneous interface biopsy in dry-aspiration cases of chronic periprosthetic joint infections: a technique for preoperative isolation of the infecting organism.
abstract: OBJECTIVE
  Preoperative identification of the infecting micro-organism is of paramount importance in the treatment protocol for chronic periprosthetic joint infections, as it enables selection of the most appropriate antibiotic treatment. Preoperative joint aspiration, the most commonly used sampling technique, has proven to have a broad range of sensitivity values and the frequency of dry aspirations has not been well assessed. In such dry-tap cases a biopsy sample could be an option. The purpose of this study was to assess the diagnostic accuracy of percutaneous interface biopsy (PIB) in isolating the infecting organism in cases of chronic Periprosthetic Joint Infection (PJI) and dry-tap event. The basic technique is to harvest and culture a sample from the periprosthetic interface membrane by a percutaneous technique in the preoperative period.
  
  
  METHODS
  A retrospective study was done involving 24 consecutive patients suspected of PJI and where no fluid was obtained from the joint. Culture results from a percutaneous interface biopsy (PIB) were compared with intraoperative tissue cultures at the time of revision surgery. In all cases, a two-stage replacement was done.
  
  
  RESULTS
  The sensitivity was 88.2%; specificity was 100%. Positive predictive value was 100%, while negative predictive value was 77.9%. Accuracy was 91.6%. No technique-related complication was observed.
  
  
  CONCLUSIONS
  We conclude that PIB is a useful test for preoperative isolation of the infecting organism and could play a role in cases with dry-tap joint aspirations.
authors: Department of Orthopedic Surgery, Reconstruction and Septic Division, Hospital de Traumatología y Rehabilitación Vall d'Hebron, Passeig Vall d'Hebron 119-129, 08035, Barcelona, Spain. pscorona@gmail.com
authors: Pablo
authors: P
authors: Corona
authors: Emilia
authors: E
authors: Gil
authors: Ernesto
authors: E
authors: Guerra
authors: Francisco
authors: F
authors: Soldado
authors: Carles
authors: C
authors: Amat
authors: Xavier
authors: X
authors: Flores
authors: Carles
authors: C
authors: Pigrau
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001170:Arthritis, Infectious / Q000175:diagnosis* / Q000382:microbiology; D001419:Bacteria / Q000302:isolation & purification*; D001706:Biopsy / Q000379:methods; D005260:Female; D006621:Hip Joint / Q000382:microbiology / Q000473:pathology*; D006801:Humans; D007719:Knee Joint / Q000382:microbiology / Q000473:pathology*; D008297:Male; D008826:Microbial Sensitivity Tests; D008828:Microbiological Techniques; D008875:Middle Aged; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology; D012086:Reoperation; D012189:Retrospective Studies