Migration characteristics and early clinical results of a novel-finned press-fit acetabular cup

Wien Klin Wochenschr. 2014 Apr;126(7-8):208-11. doi: 10.1007/s00508-013-0488-y. Epub 2014 Jan 18.


Background: Ana Nova® is a novel-finned press-fit acetabular cup which showed superior biomechanical characteristics in an experimental set-up. Using Einzel Bild Röntgen Analyse (EBRA) measurements should offer the opportunity to predict implant survival at an early stage. The purpose of this study was to assess migration and clinical outcome 2 years after total hip replacement by a novel-finned press-fit acetabular cup.

Methods: In this study, migration and clinical results of the implant were prospectively assessed in 67 patients. Clinical outcome was assessed using the Harris hip score (HHS). Migration analyses were performed using the computer assisted EBRA system. Data were analyzed for normal distribution using the Kolmogorov-Smirnov test. Group comparisons were performed using the analysis of variance (ANOVA) test. P-values less than 0.05 were considered statistically significant.

Results: At 2 years after surgery, none of the implants needed revision and HHS increased from 39.7 up to 92.2. In contrast to the beneficial clinical outcome, 17 of 44 patients showed increased total migration ( 1 mm/2a).

Conclusions: Adverse migration data in this study might predict aseptic loosening and decreased survival of the implant. According to previous studies, it is possible that this effect occurred because of limited accuracy of the EBRA system. In our opinion, migration analyses may not be recommended as a screening tool in a 2 year follow-up.

Publication types

  • Clinical Trial

MeSH terms

  • Acetabulum / surgery*
  • Adult
  • Aged
  • Arthroplasty, Replacement, Hip / adverse effects*
  • Equipment Failure Analysis
  • Female
  • Femur Head Necrosis / complications
  • Femur Head Necrosis / diagnostic imaging
  • Femur Head Necrosis / surgery*
  • Hip Prosthesis / adverse effects*
  • Humans
  • Joint Instability / diagnostic imaging
  • Joint Instability / etiology*
  • Joint Instability / surgery*
  • Male
  • Middle Aged
  • Osteoarthritis, Hip / complications
  • Osteoarthritis, Hip / diagnostic imaging
  • Osteoarthritis, Hip / surgery*
  • Pilot Projects
  • Pressure
  • Prosthesis Design
  • Prosthesis Failure
  • Prosthesis Fitting / adverse effects
  • Radiography
  • Reoperation
  • Treatment Outcome