title: Painful infection at the site of hip prosthesis: CT imaging.
abstract: OBJECTIVE
  To prospectively determine the accuracy of computed tomography (CT) in the detection of painful infection at the site of hip prosthesis before surgery.
  
  
  METHODS
  Helical CT examinations of hip prostheses were prospectively performed before surgery after a standard clinical and radiologic examination of 65 patients. CT scans and conventional radiographs were reviewed for periprosthetic bone abnormalities, and CT scans were reviewed for periprosthetic soft-tissue abnormalities (joint distention, fluid-filled bursae, and fluid collection in muscles and perimuscular fat). Patients subsequently underwent revision arthroplasty within 1 month, and infection was diagnosed in 12 (19%) patients.
  
  
  RESULTS
  Infection was detected clinically in 25% of patients. Periprosthetic bone abnormalities did not allow differentiation of infection from complications not related to sepsis, except for periostitis, with 100% specificity but only 16% sensitivity. Soft-tissue findings were accurate for detection of infection, with 100% sensitivity and 87% specificity. Fluid collection in muscles and perimuscular fat had a 100% positive predictive value, and absence of joint distention had a 96% negative predictive value.
  
  
  CONCLUSIONS
  CT is accurate in the diagnosis of painful infection at the site of a hip prosthesis on the basis of soft-tissue findings, whereas periprosthetic bone abnormalities are not useful.
authors.affiliation: Department of Radiology, Hôpital Lapeyronie, 371 avenue du Doyen Gaston Giraud, 34295 Montpellier Cedex 5, France. c-cyteval@chu-montpellier.fr
authors.forename: Catherine
authors.initials: C
authors.lastname: Cyteval
authors.forename: Vivien
authors.initials: V
authors.lastname: Hamm
authors.forename: M Pierre
authors.initials: MP
authors.lastname: Sarrabère
authors.forename: F Michel
authors.initials: FM
authors.lastname: Lopez
authors.forename: Philippe
authors.initials: P
authors.lastname: Maury
authors.forename: Patrice
authors.initials: P
authors.lastname: Taourel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed