title: Modular sleeves with ceramic heads in isolated acetabular cup revision in younger patients-laboratory and experimental analysis of suitability and clinical outcomes.
abstract: OBJECTIVE
  One possibility in hip arthroplasty revisions is to combine a modular ceramic head with an adapter or sleeve in isolated acetabular cup replacement. This study consisted of an experimental part to analyse the reliability of taper damage predictions, and a clinical part to analyse the outcomes of modular ceramic head implantation in a case series of isolated cup replacements.
  
  
  METHODS
  Analysis of scratch size on 11 explanted hip stems were examined macroscopically and by stereomicroscopy to classify damage to the conical taper. The second part consisted of a prospective analysis of isolated cup revisions using a modular ceramic head, performed in two orthopedic centres.
  
  
  RESULTS
  Analysis of scratch size on the taper yielded inter-observer correlations of 0.545-0.909; comparison with stereomicroscopic data recordings yielded a moderate correlation, with values between 0.545 and 0.090. The clinical study included 47 isolated acetabular cup revisions involving modular ceramic heads. Ceramic head failure did not occur during the average clinical and radiological observation period of 26 months. Mean Harris Hip Score (HHS) at follow-up was 70 points.
  
  
  CONCLUSIONS
  From these results, it can be concluded that damage to the implanted stem taper cannot be reliably predicted intraoperatively. Nevertheless, the clinical outcomes did show that there were no problems with the ceramic heads over the short observation period. The application of modular ceramic heads in younger patients requiring isolated cup replacement requires proper risk-benefit analysis, but is possible and appears to be a safe procedure.
authors.affiliation: Department of Orthopaedics and Traumatology, Albert-Ludwigs-University Freiburg, Freiburg, Germany. peter.helwig@uniklinik-freiburg.de
authors.forename: Peter
authors.initials: P
authors.lastname: Helwig
authors.forename: Lukas
authors.initials: L
authors.lastname: Konstantinidis
authors.forename: Anja
authors.initials: A
authors.lastname: Hirschmüller
authors.forename: Anke
authors.initials: A
authors.lastname: Bernstein
authors.forename: Oliver
authors.initials: O
authors.lastname: Hauschild
authors.forename: Norbert P
authors.initials: NP
authors.lastname: Südkamp
authors.forename: Björn G
authors.initials: BG
authors.lastname: Ochs
mesh_terms: D000077:Acetabulum; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods*; D002516:Ceramics; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D012086:Reoperation; D012189:Retrospective Studies; D013499:Surface Properties; D016896:Treatment Outcome