title: Deformation of the Durom acetabular component and its impact on tribology in a cadaveric model--a simulator study.
abstract: BACKGROUND
  Recent studies have shown that the acetabular component frequently becomes deformed during press-fit insertion. The aim of this study was to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the Durom large head metal-on-metal (MOM) total hips in simulators.
  
  
  METHODS
  Six Durom cups impacted into reamed acetabula of fresh cadavers were used as the experimental group and another 6 size-paired intact Durom cups constituted the control group. All 12 Durom MOM total hips were put through a 3 million cycle (MC) wear test in simulators.
  
  
  RESULTS
  The 6 cups in the experimental group were all deformed, with a mean deformation of 41.78 ± 8.86 µm. The average volumetric wear rate in the experimental group and in the control group in the first million cycle was 6.65 ± 0.29 mm(3)/MC and 0.89 ± 0.04 mm(3)/MC (t = 48.43, p = 0.000). The ion levels of Cr and Co in the experimental group were also higher than those in the control group before 2.0 MC. However there was no difference in the ion levels between 2.0 and 3.0 MC.
  
  
  CONCLUSIONS
  This finding implies that the non-modular acetabular component of Durom total hip prosthesis is likely to become deformed during press-fit insertion, and that the deformation will result in increased volumetric wear and increased ion release.
  
  
  CONCLUSIONS
  This study was determined to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the prosthesis. Deformation of the cup after implantation increases the wear of MOM bearings and the resulting ion levels. The clinical use of the Durom large head prosthesis should be with great care.
authors.affiliation: Department of Orthopedics, the First Affiliated Hospital with Nanjing Medical University, Nanjing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Zhefeng
authors.initials: Z
authors.lastname: Chen
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Gu
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Weiding
authors.initials: W
authors.lastname: Cui
authors.forename: Weimin
authors.initials: W
authors.lastname: Fan
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D019644:Arthroplasty, Replacement, Hip; D002102:Cadaver; D017276:Friction; D006622:Hip Prosthesis / Q000592:standards*; D006801:Humans; D008153:Lubrication; D008297:Male; D008422:Materials Testing / Q000379:methods; D008670:Metals / Q000737:chemistry; D008875:Middle Aged; D011475:Prosthesis Failure
chemical_list: D008670:Metals