title: Diagnostic work-up strategy for periprosthetic joint infections after total hip and knee arthroplasty: a 12-year experience on 320 consecutive cases.
abstract: BACKGROUND
  Elective knee and hip arthroplasty is followed by infections in currently about 0.5-2.0 % of cases - a figure which is on the increase due to the rise in primary implants. Correct diagnosis early on is essential so that appropriate therapy can be administered. This work presents a retrospective analysis of the diagnoses of patients suffering infections after total hip or knee arthroplasty.
  
  
  METHODS
  320 patients with prosthetic joint infection (PJI) following knee or hip arthroplasty were identified. They comprised a) 172 patients with an infection after total hip arthroplasty (THA): 56 % females (n = 96) and 44 % males (n = 76) with a mean age of 70.9 (39-92) years; and 148 patients with an infection after total knee arthroplasty (TKA): 55 % females (n = 82) and 45 % males (n = 66) with a mean age of 70.7 (15-87) years.
  
  
  RESULTS
  Although significantly more TKA than THA patients reported pain, erythema, a burning sensation and swelling, no differences between the two groups were observed with respect to dysfunction, fever or fatigue. However, significant differences were noted in the diagnosis of loosening (THA 55 %, TKA 31 %, p < 0.001) and suspected infection using conventional X-rays (THA 61 %, TKA 29 %, p < 0.001). FDG-PET-CT produced very good results in nearly 95 % of cases. There were no differences between THA and TKA patients regarding levels of inflammation markers. Histological evaluation proved to be significantly better than microbiological analysis.
  
  
  CONCLUSIONS
  The clinical picture may be non-specific and not show typical inflammatory symptoms for a long time, particularly in PJI of the hip. As imaging only provides reliable conclusions after the symptoms have persisted for a long time, morphological imaging is not suitable for the detection of early infections. FDG-PT-CT proved to be the most successful technique and is likely to be used more frequently in future. Nevertheless, there are currently no laboratory parameters which are suitable for the reliable primary diagnosis of PJI. Diagnosis requires arthrocentesis, and the fluid obtained should always be examined both microbiologically and histologically.
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Zajonz
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Wuthe
authors.affiliation: Department of Nuclear medicine, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Solveig
authors.initials: S
authors.lastname: Tiepolt
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Brandmeier
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Prietzel
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Georg Freiherr
authors.initials: GF
authors.lastname: von Salis-Soglio
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Roth
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Josten
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Christoph-E
authors.initials: CE
authors.lastname: Heyde
authors.affiliation: Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University Hospital Leipzig, Liebigstrasse 20, 04103 Leipzig, Germany.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ghanem
keywords: Diagnosis; Prosthetic joint infection; THA; TKA