title: Development and Verification of Novel Porous Titanium Metaphyseal Cones for Revision Total Knee Arthroplasty.
abstract: Porous metaphyseal cones are widely used in revision knee arthroplasty. A new system of porous titanium metaphyseal cones has been designed based on the femoral and tibial morphology derived from a computed tomography-based anatomical database. The purpose of this study is to evaluate the initial mechanical stability of the new porous titanium revision cone system by measuring the micromotion under physiologic loading compared with a widely-used existing porous tantalum metaphyseal cone system.
  
  
  
  The new cones were designed to precisely fit the femoral and tibial anatomy, and 3D printing technology was used to manufacture these porous titanium cones. The stability of the new titanium cones and the widely-used tantalum cones were compared under physiologic loading conditions in bench top test model.
  
  
  
  The stability of the new titanium cones was either equivalent or better than the tantalum cones. The new titanium femoral cone construct had significantly less micromotion compared with the traditional femoral cone construct in 5 of the 12 directions measured (P < .05), whereas no statistical difference was found in 7 directions. The new porous titanium metaphyseal tibial cones demonstrated less micromotion in medial varus/valgus (P = .004) and posterior compressive micromotion (P = .002) compared with the traditional porous tantalum system.
  
  
  
  The findings of this biomechanical study demonstrate satisfactory mechanical stability of an anatomical-based porous titanium metaphyseal cone system for femoral and tibial bone loss as measured by micromotion under physiologic loading. The new cone design, in combination with instrumentation that facilitates surgical efficiency, is encouraging. Long-term clinical follow-up is warranted.
authors.affiliation: Stryker, Mahwah, New Jersey.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Faizan
authors.affiliation: Stryker, Mahwah, New Jersey.
authors.forename: Manoshi
authors.initials: M
authors.lastname: Bhowmik-Stoker
authors.affiliation: Stryker, Mahwah, New Jersey.
authors.forename: Vincent
authors.initials: V
authors.lastname: Alipit
authors.affiliation: Stryker, Mahwah, New Jersey.
authors.forename: Amanda E
authors.initials: AE
authors.lastname: Kirk
authors.affiliation: Department of Orthopaedic Surgery, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Viktor E
authors.initials: VE
authors.lastname: Krebs
authors.affiliation: Mount Sinai Beth Israel Medical Center, New York, New York.
authors.forename: Steven F
authors.initials: SF
authors.lastname: Harwin
authors.affiliation: Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: R Michael
authors.initials: RM
authors.lastname: Meneghini
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods*; D001696:Biomechanical Phenomena; D004867:Equipment Design; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D016062:Porosity; D012086:Reoperation; D013635:Tantalum; D013977:Tibia / Q000601:surgery; D014025:Titanium / Q000737:chemistry*
chemical_list: D013635:Tantalum; D014025:Titanium
keywords: 3D printing; knee revision cones; metaphyseal cones; micromotion; porous titanium; revision knee arthroplasty