title: High failure rate of a new pressfit cup in mid-term follow-up.
abstract: BACKGROUND
  Unacceptably high rates of loosening of a novel cementless cup system (Mathys, SeleXys TH+) have been reported. In this study, our mid-term-results with the SeleXys TH+ cup are compared with an established pressfit cup (Ceraver, Cerafit-R).
  
  
  METHODS
  Between 2008 and 2011, a total of 407 implantations, 19 of them bilaterally, were conducted on 388 patients with the implants in question. A total of 280 cups were available for follow-up. Of these, 160 SeleXys TH+ cups and 120 Cerafit-R cups had been used.
  
  
  RESULTS
  The mean follow-up period was 48.6 months (min. 28, max. 75). A total of 18 cases of loosening were found in the SeleXys TH+ group. Of these, one was of a traumatic nature and one was of septic origin. This left 16 cases of aseptic, atraumatic loosening (10% loosening rate). In the Cerafit-R group, only two cases (1.7%) of loosening were seen over the same period. Both were of traumatic origin. No cases of aseptic, atraumatic loosening were seen in the follow-up period. Further, significantly more cases of loosening were observed in women than in men with the SeleXys cup.
  
  
  CONCLUSIONS
  The SeleXys TH+ cup shows an unacceptably high failure rate after six years. The time of revision is not limited to the first months after implantation, which means that close clinical and radiological controls will continue to be necessary in future in patients treated with SeleXys TH+ cups. Level of Evidenve: III (retrospective cohort study).
authors.affiliation: Orthopedic Department, Campus Eisenberg, Friedrich-Schiller University Jena, Campus Eisenberg, Klosterlausnitzer Straße 81, 07607, Eisenberg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Brodt
authors.forename: Georg
authors.initials: G
authors.lastname: Matziolis
authors.forename: Christoph
authors.initials: C
authors.lastname: Windisch
authors.forename: Andreas
authors.initials: A
authors.lastname: Gosse
authors.forename: Matthias
authors.initials: M
authors.lastname: Spalteholz
authors.forename: Ralf Herbert
authors.initials: RH
authors.lastname: Gahr
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies