title: Finite element model of a novel short stemmed total hip arthroplasty implant developed from cross sectional CT scans.
abstract: BACKGROUND
  Numerous short stemmed total hip arthroplasty (THA) implants have been introduced over the last decades. It is questionable if little differences between the implant designs affect stress shielding and bone remodeling. The finite element analysis allows an evaluation of the design rationale of the implant without negative side effects for the patient.
  
  
  OBJECTIVE
  We investigated a relatively new short stemmed implant designed from clustered CT datasets of proximal femurs. How does the implant affect femoral bone remodeling? Can we see a positive effect on bone remodeling from the CT based design?
  
  
  METHODS
  We used a Finite Element Model that was validated by a prospective dual-energy-x-ray-absorptiometry study to calculate apparent bone density.
  
  
  RESULTS
  Apparent bone density (ABD) decreased by 2.3% in the entire femur. Bone mass loss was pronounced in the proximal calcar region. Little ABD increase was seen in the lateral aspect of the cortical ring, in the minor trochanter area and at the lateral aspect of the stem.
  
  
  CONCLUSIONS
  ABD reduction occurs in the proximal regions of the femur. The overall bone mass loss was little after THA with the investigated implant. The specific design seems to have no major effect on stress shielding or load distribution.
authors.affiliation: Department of Orthopaedic Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lerch
authors.forename: Nelly
authors.initials: N
authors.lastname: Weigel
authors.forename: Henning
authors.initials: H
authors.lastname: Windhagen
authors.forename: Max
authors.initials: M
authors.lastname: Ettinger
authors.forename: Fritz
authors.initials: F
authors.lastname: Thorey
authors.forename: Agnes
authors.initials: A
authors.lastname: Kurtz
authors.forename: Christina
authors.initials: C
authors.lastname: Stukenborg-Colsman
authors.forename: Anas
authors.initials: A
authors.lastname: Bouguecha
mesh_terms: D015502:Absorptiometry, Photon; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D015519:Bone Density; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology; D006622:Hip Prosthesis / Q000592:standards; D006801:Humans; D008954:Models, Biological; D014057:Tomography, X-Ray Computed
keywords: Total hip arthroplasty (THA); finite element analysis (FEA); periprosthetic bone remodeling; short stem