title: Efficacy of a novel PCR- and microarray-based method in diagnosis of a prosthetic joint infection.
abstract: OBJECTIVE
  Polymerase chain reaction (PCR) methods enable detection and species identification of many pathogens. We assessed the efficacy of a new PCR and microarray-based platform for detection of bacteria in prosthetic joint infections (PJIs).
  
  
  METHODS
  This prospective study involved 61 suspected PJIs in hip and knee prostheses and 20 negative controls. 142 samples were analyzed by Prove-it Bone and Joint assay. The laboratory staff conducting the Prove-it analysis were not aware of the results of microbiological culture and clinical findings. The results of the analysis were compared with diagnosis of PJIs defined according to the Musculoskeletal Infection Society (MSIS) criteria and with the results of microbiological culture.
  
  
  RESULTS
  38 of 61 suspected PJIs met the definition of PJI according to the MSIS criteria. Of the 38 patients, the PCR detected bacteria in 31 whereas bacterial culture was positive in 28 patients. 15 of the PJI patients were undergoing antimicrobial treatment as the samples for analysis were obtained. When antimicrobial treatment had lasted 4 days or more, PCR detected bacteria in 6 of the 9 patients, but positive cultures were noted in only 2 of the 9 patients. All PCR results for the controls were negative. Of the 61 suspected PJIs, there were false-positive PCR results in 6 cases.
  
  
  CONCLUSIONS
  The Prove-it assay was helpful in PJI diagnostics during ongoing antimicrobial treatment. Without preceding treatment with antimicrobials, PCR and microarray-based assay did not appear to give any additional information over culture.
authors.affiliation: Department of Orthopedics , Peijas Hospital, Helsinki University Central Hospital.
authors.forename: Leena
authors.initials: L
authors.lastname: Metso
authors.forename: Minna
authors.initials: M
authors.lastname: Mäki
authors.forename: Päivi
authors.initials: P
authors.lastname: Tissari
authors.forename: Ville
authors.initials: V
authors.lastname: Remes
authors.forename: Pasi
authors.initials: P
authors.lastname: Piiparinen
authors.forename: Juha
authors.initials: J
authors.lastname: Kirveskari
authors.forename: Eveliina
authors.initials: E
authors.lastname: Tarkka
authors.forename: Veli-Jukka
authors.initials: VJ
authors.lastname: Anttila
authors.forename: Martti
authors.initials: M
authors.lastname: Vaara
authors.forename: Kaisa
authors.initials: K
authors.lastname: Huotari
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001431:Bacteriological Techniques / Q000379:methods; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects / Q000382:microbiology; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000302:isolation & purification*; D046888:Tissue Array Analysis / Q000379:methods*