title: [Survival rate of a cement-free cup of titanium with laser structured surface].
abstract: OBJECTIVE
  So far no clinical results concerning the survival rates of cementless pure titanium cups with laser-structured surfaces exist. This study was performed to evaluate our results for the Alphasegment acetabular component (Alphanorm).
  
  
  METHODS
  Retrospective analysis of 50 cups in 45 patients was performed (operations performed between November 1995 and January 1998). The average age at the time of the implantation was 65.1 years. Dysplastic hips and revisions were excluded. The survival rate was calculated according to the Kaplan-Meier analysis with the end point defined as the revision surgery of the cup.
  
  
  RESULTS
  The average follow-up period was 2.9 (0.6-4.0) years. Two patients (i.e., two implants) died during the observation period, none were lost for follow-up. Six of the cups had to be revised due to aseptic loosening. The survival rate at 3.2 years after implantation was 87%. None of the stems had to be revised.
  
  
  CONCLUSIONS
  Further use of the cementless hemispherical pure titanium cup with laser-structured surface cannot be recommended. The observed prevalence of loosening for the Alphasegment acetabular components was higher than for other cups. Close follow-up of patients with this type of implant is necessary.
authors.affiliation: Othopädische Universitätsklinik Essen. thomas.lichtinger@uni-essen.de
authors.forename: T K
authors.initials: TK
authors.lastname: Lichtinger
authors.forename: R T
authors.initials: RT
authors.lastname: Müller
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019544:Equipment Failure Analysis; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D013499:Surface Properties; D016019:Survival Analysis; D014025:Titanium
chemical_list: D014025:Titanium