title: Results of a Modular Femoral Revision System Before and After Taper Roller Hardening in Total Hip Arthroplasty.
abstract: BACKGROUND
  Modular component options can aid in addressing complex femoral reconstructions in total hip arthroplasty (THA) by allowing for customization of version control and proximal to distal sizing. However, component breakage at the modular junction has occurred, particularly in the presence of poor bone stock. A taper roller hardening (RH) process was developed to strengthen the modular junction to reduce breakage. The purpose of this study is to review THA patients before and after taper roller hardening to compare stem survival and frequency of breakage.
  
  
  METHODS
  A query of our practice registry revealed 183 consented patients (202 THA) who underwent THA with a modular femoral revision component between January 1993 and September 2010. Forty THA were done before (non-RH) and 162 were done after taper roller hardening.
  
  
  RESULTS
  Mean follow-up was seven and 17 years in the RH and non-RH groups respectively. In the non-RH group, 15% were revised for component breakage versus 2% in the RH group. Overall, 35% non-RH versus 8% RH stems have been revised. Kaplan-Meier survival at 10 years with endpoint of stem revision for breakage revealed 84.2% ( ±6.0%) non-RH compared with 95.5% ( ±2.2%) RH (p=0.0033), and with endpoint of stem revision for any reason, 65.0% ( ±7.5%) non-RH compared with 80.3% ( ±3.7%) RH (p=0.0022).
  
  
  CONCLUSIONS
  Results indicate that the taper roller hardening process was successful in improving durability of a modular femoral revision system and reducing frequency of component breakage for patients who require treatment of the deficient femur in complex primary and revision THA.
authors.affiliation: Spectrum Orthopedics, North Canton, Ohio.
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Marshall
authors.affiliation: Joint Implant Surgeons, Inc., New Albany, Ohio, Chief Executive Officer and President, White Fence Surgical Suites, White Fence Surgical Suites, New Albany, Ohio, Mount Carmel Health System, Columbus, Ohio.
authors.forename: Keith R
authors.initials: KR
authors.lastname: Berend
authors.affiliation: Joint Implant Surgeons, Inc., New Albany, Ohio, Mount Carmel Health System, Columbus, Ohio.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Morris
authors.affiliation: oint Implant Surgeons, Inc., New Albany, Ohio.
authors.forename: Joanne B
authors.initials: JB
authors.lastname: Adams
authors.affiliation: Joint Implant Surgeons, Inc., New Albany, Ohio, Department of Orthopaedics, The Ohio State University, Wexner Medical Center, Columbus, Ohio, Mount Carmel Health System, Columbus, Ohio.
authors.forename: Adolph V
authors.initials: AV
authors.lastname: Lombardi
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D005269:Femur / Q000601:surgery; D006622:Hip Prosthesis / Q000009:adverse effects / Q000706:statistics & numerical data; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies