title: Do Stem Taper Microgrooves Influence Taper Corrosion in Total Hip Arthroplasty? A Matched Cohort Retrieval Study.
abstract: Previous studies identified imprinting of the stem morphology onto the interior head bore, leading researchers to hypothesize an influence of taper topography on mechanically assisted crevice corrosion. The purpose of this study was to analyze whether microgrooved stem tapers result in greater fretting corrosion damage than smooth stem tapers.
  
  
  
  A matched cohort of 120 retrieved head-stem pairs from metal-on-polyethylene bearings was created controlling for implantation time, flexural rigidity, apparent length of engagement, and head size. There were 2 groups of 60 heads each, mated with either smooth or microgrooved stem tapers. A high-precision roundness machine was used to measure and categorize the surface morphology. Fretting corrosion damage at the head-neck junction was characterized using the Higgs-Goldberg scoring method. Fourteen of the most damaged heads were analyzed for the maximum depth of material loss and focused ion beam cross-sectioned to view oxide and base metal.
  
  
  
  Fretting corrosion damage was not different between the 2 cohorts at the femoral head (P = .14, Mann-Whitney) or stem tapers (P = .35). There was no difference in the maximum depths of material loss between the cohorts (P = .71). Cross-sectioning revealed contact damage, signs of micro-motion, and chromium-rich oxide layers in both cohorts. Microgroove imprinting did not appear to have a different effect on the fretting corrosion behavior.
  
  
  
  The results of this matched cohort retrieval study do not support the hypothesis that taper surfaces with microgrooved stems exhibit increased in vivo fretting corrosion damage or material release.
authors.affiliation: Implant Research Center, Drexel University, Philadelphia, Pennsylvania.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Arnholt
authors.affiliation: Implant Research Center, Drexel University, Philadelphia, Pennsylvania.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: MacDonald
authors.affiliation: Exponent, Inc, Philadelphia, Pennsylvania.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Underwood
authors.affiliation: Exponent, Inc, Atlanta, Georgia.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Guyer
authors.affiliation: Center for the Evaluation of Implant Performance, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Clare M
authors.initials: CM
authors.lastname: Rimnac
authors.affiliation: Implant Research Center, Drexel University, Philadelphia, Pennsylvania; Exponent, Inc, Philadelphia, Pennsylvania.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kurtz
authors.affiliation: Sinai Hospital of Baltimore, Baltimore, Maryland.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Mont
authors.affiliation: Hartzband Center for Hip & Knee Replacement, Paramus, New Jersey.
authors.forename: Gregg R
authors.initials: GR
authors.lastname: Klein
authors.affiliation: Presbyterian Medical Center, University of Pennsylvania Health Systems, Philadelphia, Pennsylvania.
authors.forename: Gwo-Chin
authors.initials: GC
authors.lastname: Lee
authors.affiliation: Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania.
authors.forename: Antonia F
authors.initials: AF
authors.lastname: Chen
authors.affiliation: University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Hamlin
authors.affiliation: Tennessee Orthopaedic Clinics, Knoxville, Tennessee.
authors.forename: Harold E
authors.initials: HE
authors.lastname: Cates
authors.affiliation: Jewish Hospital and St. Mary's Health Care, Louisville, Kentucky.
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Malkani
authors.affiliation: Center for the Evaluation of Implant Performance, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kraay
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation; D002858:Chromium Alloys; D015331:Cohort Studies; D003343:Corrosion; D005260:Female; D005270:Femur Head / Q000601:surgery; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure
chemical_list: D002858:Chromium Alloys; D020959:Polyethylene
keywords: corrosion; fretting; mechanically assisted crevice corrosion; microgrooves; taper