title: Use of F-18 fluoride PET to differentiate septic from aseptic loosening in total hip arthroplasty patients.
abstract: OBJECTIVE
  The preoperative differentiation of aseptic and septic loosening following a total hip arthroplasty (THA) remains a challenging issue for clinicians to which several molecular imaging techniques have been applied. In our current study, we used F-18 fluoride positron emission tomography (PET) to evaluate THA cases with stable, septic or septic loosened implants to assess the possibility of differentiating these clinical settings using a novel uptake-type classification approach.
  
  
  METHODS
  A total of 65 joints were enrolled in this prospective study comprising 27 asymptomatic stable hips (control group), 11 painful hips conservatively treated after THA due to a suspicion of loosening, and 27 painful hips surgically treated after THA. PET imaging was classified into 3 types according to the uptake pattern. The maximum standardized uptake value (SUVmax) was then measured for each joint. A final diagnosis was made via tissue examinations of surgically treated cases, and by serological and radiographic findings in conservatively treated cases.
  
  
  RESULTS
  There were significant differences found between the SUVmax values for the aseptic and septic loosening THA cases. In the diagnosis of infection with type 3 pattern, the sensitivity and specificity were measured at 0.95 and 0.98 for all cases, and 0.95 and 0.88 for surgically treated cases, respectively.
  
  
  CONCLUSIONS
  The results of our current study demonstrate that F-18 fluoride PET has considerable potential as a method for differentiating septic from aseptic loosening following a THA. The type classification of the uptake pattern can be performed relatively simply, and quantifications using the SUVmax values can then provide an objective evaluation.
authors: Department of Orthopaedic Surgery, Yokohama City University, School of Medicine, Yokohama, Japan. naomik58@aol.com
authors: Naomi
authors: N
authors: Kobayashi
authors: Yutaka
authors: Y
authors: Inaba
authors: Hyonmin
authors: H
authors: Choe
authors: Hiroyuki
authors: H
authors: Ike
authors: Hiroshi
authors: H
authors: Fujimaki
authors: Taro
authors: T
authors: Tezuka
authors: Yasuhide
authors: Y
authors: Hirata
authors: Ukihide
authors: U
authors: Tateishi
authors: Tomio
authors: T
authors: Inoue
authors: Tomoyuki
authors: T
authors: Saito
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D016022:Case-Control Studies; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics; D006801:Humans; D049268:Positron-Emission Tomography; D011475:Prosthesis Failure; D012372:ROC Curve; D018805:Sepsis / Q000000981:diagnostic imaging*
chemical_list: D005462:Fluorine Radioisotopes