title: MRI as a problem-solving tool in unexplained failed total hip replacement following conventional assessment.
abstract: OBJECTIVE
  To evaluate MRI as a problem-solving tool for patients with an unexplained failed total hip replacement following conventional radiological assessment.
  
  
  METHODS
  Patients' informed consent was obtained in all cases. Institutional review board approval was obtained. Twenty-eight patients with unexplained failed total hip replacements following conventional radiological assessment underwent additional MR imaging with an optimised turbo-spin echo sequence. Images were reviewed by two musculoskeletal radiologists by consensus and compared with findings at surgery, or following response to image-guided intervention or clinical follow-up.
  
  
  RESULTS
  Of the 28 patients, MRI revealed an unsuspected diagnosis explaining the cause of prosthesis failure in 15 patients. In eight of 15 patients in this group, subsequent minimally invasive image-guided intervention obviated the need for revision total hip replacement. No cause for prosthesis failure was identified in 13 patients.
  
  
  CONCLUSIONS
  MRI may be successfully undertaken in patients following total hip replacement, and, when performed, it frequently leads to an unsuspected diagnosis, allowing informed patient treatment. In this study it allowed the identification of an unsuspected diagnosis in over 50% of cases.
authors.affiliation: Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin 11, Ireland. ciaranjohnston@yahoo.co.uk
authors.forename: Ciaran
authors.initials: C
authors.lastname: Johnston
authors.forename: Jennifer
authors.initials: J
authors.lastname: Kerr
authors.forename: Stephanie
authors.initials: S
authors.lastname: Ford
authors.forename: John
authors.initials: J
authors.lastname: O'byrne
authors.forename: Stephen
authors.initials: S
authors.lastname: Eustace
mesh_terms: D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation; D019544:Equipment Failure Analysis / Q000379:methods; D005260:Female; D006621:Hip Joint / Q000473:pathology* / Q000601:surgery*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000209:etiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D016896:Treatment Outcome