title: Is wear debris responsible for failure in alumina-on-alumina implants?
abstract: OBJECTIVE
  Ceramic-on-ceramic articulation is an attractive alternative to metal-on-polyethylene (PE) bearings, but little is known about the in vivo effects induced by dissemination of alumina wear debris in the periprosthetic tissues. We hypothesized that wear debris is not the main factor responsible for loosening and failure of the implant but that mechanical problems caused by incorrect surgical technique, prosthetic design, or trauma, may cause instability of the implants and result in production of wear debris.
  
  
  METHODS
  Clinical, radiographic, laboratory, and microbiological data from 30 consecutive patients with failed alumina-on-alumina arthroplasties, 19 with screwed socket and 11 with press-fit socket, were systematically collected and evaluated. Retrieved peri-implant tissues and prosthesis wear were also analyzed.
  
  
  CONCLUSIONS
  Loosening was due to malpositioning, primary mechanical instability, trauma, or infection. Bone stock was generally preserved, even if screwed implants showed higher levels of osteolysis. Variable implant wear and tissue macrophage reaction were present but activation of giant cells/osteoclasts was not induced, and no correlation between histocytic reaction and the level of osteolysis was found. These findings indicate that, in contrast to the situation with metal-on-PE bearings, wear debris and occasional osteolysis were the effect rather than the cause of failure of ceramic-on-ceramic implants, and that press-fit socket fixation was the socket fixation design of preference.
authors.affiliation: Laboratory for Pathophysiology of Orthopaedic Implant, Bologna, Italy. lucia.savarino@ior.it
authors.forename: Lucia
authors.initials: L
authors.lastname: Savarino
authors.forename: Nicola
authors.initials: N
authors.lastname: Baldini
authors.forename: Gabriela
authors.initials: G
authors.lastname: Ciapetti
authors.forename: Andrea
authors.initials: A
authors.lastname: Pellacani
authors.forename: Armando
authors.initials: A
authors.lastname: Giunti
mesh_terms: D000328:Adult; D000368:Aged; D000537:Aluminum Oxide; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods; D002516:Ceramics; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D010014:Osteolysis / Q000209:etiology / Q000473:pathology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D013499:Surface Properties
chemical_list: D000537:Aluminum Oxide