title: Osteolysis in patients with a metal-on-metal hip arthroplasty.
abstract: BACKGROUND
  Despite design and manufacturing improvements in contemporary metal-on-metal hip replacements, the problem of wear particles persists. The local and systemic biological consequences of this ionic debris have been the subject of much investigation and it has become clear that cell-mediated delayed-type hypersensitivity reactions are a discrete mode of osteolysis in susceptible patients.
  
  
  METHODS
  We have carried out a consecutive series of 125 primary hip replacements using the Metasul (Zimmer, Warsaw, IN, USA) bearing couple. The radiographs, periprosthetic tissue and retrieved implants of patients undergoing revision for osteolysis were analysed.
  
  
  RESULTS
  Three patients underwent revision procedures during a follow-up period of 3-9 years. Histological analysis showed a perivascular lymphocytic infiltrate of the pseudocapsule. Infection was excluded in each patient, there was no implant loosening and no evidence of impingement between trunion and acetabular component.
  
  
  CONCLUSIONS
  We report a prevalence of 2.6% of patients displaying femoral osteolysis associated with characteristic clinical and histological findings.
authors.affiliation: Department of Orthopaedic Surgery, Royal Melbourne Hospital, Melbourne, Victoria, Australia. ashleycarr@optusnet.com.au
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Carr
authors.forename: Richard
authors.initials: R
authors.lastname: DeSteiger
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D016025:Bone Transplantation / Q000379:methods; D020878:Device Removal; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000175:diagnosis / Q000601:surgery*; D010014:Osteolysis / Q000209:etiology* / Q000601:surgery; D011474:Prosthesis Design; D011475:Prosthesis Failure; D020127:Recovery of Function; D012086:Reoperation / Q000379:methods; D018570:Risk Assessment; D012494:Sampling Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D008670:Metals