title: Excluding infections in arthroplasty using leucocyte esterase test.
abstract: OBJECTIVE
  Periprosthetic joint infections remain a major challenge for the surgeon in modern arthroplasty. The decision on how to handle a case is often difficult due to the variety of clinical presentations. The aim of this study was to establish the leucocyte esterase test as an intra-operative rapid diagnostic tool in an unclear infected or aseptic situation.
  
  
  METHODS
  In the setting of 364 endoprosthetic joint procedures on knee, hip and shoulder, we aspirated synovial fluid before performing capsulotomy. We performed a leucocyte esterase test. The results were correlated with the pre-operative synovial fluid aspirations, the laboratory blood sample parameters (C-reactive protein, white blood cells) and the intra-operative histopathological and microbiological findings.
  
  
  RESULTS
  The leucocyte esterase test has a sensitivity of 100% and a specificity of 96.5%. The positive predictive value was 82% and the negative predictive value was 100%. Correlation with conventional methods such as serum C-reactive protein and serum white blood cells is given. The histopathological evaluation confirmed the microbiological results in all but three cases.
  
  
  CONCLUSIONS
  Based on our results and the current literature, we recommend the leucocyte esterase test as a useful tool in the diagnosis of periprosthetic joint infection.
authors.affiliation: Orthopaedic Department, HELIOS Endo-Klinik Hamburg, Holstenstraße 9, 22767, Hamburg, Germany, guenther.daniel@mh-hannover.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Guenther
authors.forename: Thomas
authors.initials: T
authors.lastname: Kokenge
authors.forename: Oliver
authors.initials: O
authors.lastname: Jacobs
authors.forename: Mohamed
authors.initials: M
authors.lastname: Omar
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.forename: Thorsten
authors.initials: T
authors.lastname: Gehrke
authors.forename: Daniel
authors.initials: D
authors.lastname: Kendoff
authors.forename: Carl
authors.initials: C
authors.lastname: Haasper
mesh_terms: D019643:Arthroplasty, Replacement; D002097:C-Reactive Protein / Q000032:analysis; D002265:Carboxylic Ester Hydrolases / Q000032:analysis*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007432:Intraoperative Period; D007720:Knee Prosthesis / Q000009:adverse effects*; D007958:Leukocyte Count; D008297:Male; D011446:Prospective Studies; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology / Q000601:surgery; D012680:Sensitivity and Specificity; D012785:Shoulder Joint / Q000382:microbiology / Q000601:surgery; D013582:Synovial Fluid / Q000378:metabolism
chemical_list: D002097:C-Reactive Protein; C021443:leukocyte esterase; D002265:Carboxylic Ester Hydrolases