title: The value of intraoperative histology in predicting infection in patients undergoing revision elbow arthroplasty.
abstract: BACKGROUND
  The perioperative diagnosis of infection in the setting of revision elbow arthroplasty may be difficult to establish. Intraoperative pathology with histology for identification of acute inflammatory changes has been reported to be of value in revision surgery after failed hip or knee arthroplasty. The purpose of this study was to study the role of intraoperative histology in the diagnosis of infection in patients undergoing revision elbow arthroplasty.
  
  
  METHODS
  From 2000 to 2007, 296 consecutive revision elbow procedures were performed at our institution. Both intraoperative histology and operative samples for culture were obtained at the time of 227 of these procedures, which form the basis of this study.
  
  
  RESULTS
  Histology was read as consistent with acute inflammation in patients undergoing thirty-three procedures (14.5%). Intraoperative cultures were positive in thirty-nine procedures (17.2%). Intraoperative histology was considered true positive (both histology and cultures positive) in twenty arthroplasties (8.8%), true negative (both histology and cultures were negative) in 175 arthroplasties (77.1%), false positive (the histology was positive but the culture was negative) in thirteen arthroplasties (5.7%), and false negative (the histology was negative but the culture was positive) in nineteen arthroplasties (8.4%). With regard to intraoperative histology, the sensitivity was 51.3%, the specificity was 93.1%, and the accuracy was 85.9%. The positive predictive value was 60.6% and the negative predictive value was 90.2%.
  
  
  CONCLUSIONS
  In our study, intraoperative histology had a high specificity and negative predictive value, but a low sensitivity and positive predictive value for predicting infection in the setting of revision elbow arthroplasty. Intraoperative histology should be used in conjunction with other studies to definitively establish the diagnosis of infection in the setting of revision elbow arthroplasty.
  
  
  METHODS
  Diagnostic level I. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for J. Sanchez-Sotelo: sanchezsotelo.joaquin@mayo.edu.
authors.forename: Shahryar
authors.initials: S
authors.lastname: Ahmadi
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lawrence
authors.forename: Bernard F
authors.initials: BF
authors.lastname: Morrey
authors.forename: Joaquin
authors.initials: J
authors.lastname: Sanchez-Sotelo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057929:Arthroplasty, Replacement, Elbow / Q000009:adverse effects*; D004551:Elbow Joint / Q000473:pathology* / Q000601:surgery; D005260:Female; D005629:Frozen Sections; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000473:pathology; D012086:Reoperation