title: The implications of 18F-FDG PET for the diagnosis of endoprosthetic loosening and infection in hip and knee arthroplasty: results from a prospective, blinded study.
abstract: BACKGROUND
  The most frequent complications of joint arthroplasty are septic or aseptic loosening of endoprostheses. Preoperative differentiation is essential, since very different treatment methods result from the diagnoses. The aim of the current study was to evaluate the clinical value of 18F-Fluoro-deoxyglucose positron emission tomography (18F-FDG PET) as a diagnostic modality for inflammation and loosening in hip and knee joint prostheses.
  
  
  METHODS
  18F-FDG-PET examinations and multiphase bone scan were performed on hip and knee endoprostheses in 27 patients prior to revision surgical procedures planned for prosthetic loosening. Intact prostheses were found at the opposite site in some patients so that additional 9 joints could be examined with the field of view of 18F-FDG PET. Verification and valuation of the PET and scintigraphic image findings were conducted by comparing them with information combined from intraoperative findings, histopathology, and microbiological investigations.
  
  
  RESULTS
  Evidence of loosening was correctly determined in 76.4% of cases using 18F-FDG-PET, and in 75% of cases using bone scan. The detection of periprosthetic inflammation using 18F-FDG-PET had a sensitivity of 100% for septic cases and of 45.5% in cases of increased abrasion and aseptic foreign-body reactions. However, reliable differentiation between abrasion-induced and bacterial-caused inflammation was not possible using 18F-FDG-PET.
  
  
  CONCLUSIONS
  18F-Fluoro-deoxyglucose positron emission tomography (18F-FDG-PET) allows reliable prediction of peri-prosthetic septical inflammatory tissue reactions. Because of the high sensitivity of this method, a negative PET result in the setting of a diagnostically unclear situation eliminates the need for revision surgery. In contrast, a positive PET result gives no clear differentiation regarding the cause of inflammation.
authors.affiliation: Department of Orthopaedic Surgery Cologne University, Joseph-Stelzmann Strasse 9, 50931 KOELN, Germany. stefan.delank@uk-koeln.de
authors.forename: K-St
authors.initials: KS
authors.lastname: Delank
authors.forename: M
authors.initials: M
authors.lastname: Schmidt
authors.forename: J W-P
authors.initials: JW
authors.lastname: Michael
authors.forename: M
authors.initials: M
authors.lastname: Dietlein
authors.forename: H
authors.initials: H
authors.lastname: Schicha
authors.forename: P
authors.initials: P
authors.lastname: Eysel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D019544:Equipment Failure Analysis / Q000379:methods; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D005549:Foreign-Body Reaction / Q000000981:diagnostic imaging / Q000209:etiology; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D012086:Reoperation; D012680:Sensitivity and Specificity; D016037:Single-Blind Method
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18