title: Silent soft tissue pathology is common with a modern metal-on-metal hip arthroplasty.
abstract: OBJECTIVE
  Adverse reactions to metal debris have been reported to be a cause of pain in metal-on-metal hip arthroplasty. We assessed the incidence of both symptomatic and asymptomatic adverse reactions in a consecutive series of patients with a modern large-head metal-on-metal hip arthroplasty.
  
  
  METHODS
  We studied the early clinical results and results of routine metal artifact-reduction MRI screening in a series of 79 large-head metal-on-metal hip arthroplasties (ASR; DePuy, Leeds, UK) in 68 patients. 75 hips were MRI scanned at mean 31 (12-52) months after surgery.
  
  
  RESULTS
  27 of 75 hips had MRI-detected metal debris-related abnormalities, of which 5 were mild, 18 moderate, and 4 severe. 8 of these hips have been revised, 6 of which were revised for an adverse reaction to metal debris, diagnosed preoperatively with MRI and confirmed histologically. The mean Oxford hip score (OHS) for the whole cohort was 21. It was mean 23 for patients with no MRI-based evidence of adverse reactions and 19 for those with adverse reactions detected by MRI. 6 of 12 patients with a best possible OHS of 12 had MRI-based evidence of an adverse reaction.
  
  
  CONCLUSIONS
  We have found a high early revision rate with a modern, large-head metal-on-metal hip arthroplasty. MRI-detected adverse rections to metal debris was common and often clinically "silent". We recommend that patients with this implant should be closely followed up and undergo routine metal artifact-reduction MRI screening.
authors.affiliation: The Centre for Hip Surgery, Wrightington Hospital, Lancashire, UK. hwj@doctors.net.uk
authors.forename: Henry
authors.initials: H
authors.lastname: Wynn-Jones
authors.forename: Rory
authors.initials: R
authors.lastname: Macnair
authors.forename: James
authors.initials: J
authors.lastname: Wimhurst
authors.forename: Nish
authors.initials: N
authors.lastname: Chirodian
authors.forename: Brian
authors.initials: B
authors.lastname: Derbyshire
authors.forename: Andoni
authors.initials: A
authors.lastname: Toms
authors.forename: John
authors.initials: J
authors.lastname: Cahir
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D002857:Chromium / Q000009:adverse effects; D003035:Cobalt / Q000009:adverse effects; D004487:Edema / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000473:pathology; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000473:pathology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D014025:Titanium / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: D002857:Chromium; D003035:Cobalt; D014025:Titanium