title: The contour of cementless femoral stem has minor effect on initial periprosthetic von Mises stress distribution. A 3-dimensional finite element analysis.
abstract: OBJECTIVE
  To evaluate periprosthetic von Mises stress distribution with cementless femoral stems of various contours.
  
  
  METHODS
  The study was carried out at the Department of Orthopaedics, Shanghai 6th Hospital, Shanghai, China between May 2008 and February 2009. Finite element models of proximal femoral replacement with 4 cementless stems (Alloclassic, Ribbed Anatomic, VerSys, and Securi-fit) of various contours were set up. Under the loading conditions of walking and stair climbing, 3-dimensional periprosthetic von Mises stresses were calculated, and the stress distribution patterns were compared.
  
  
  RESULTS
  Periprosthetic stresses were increased in level 1, 2, and 3 under the 2 loading conditions, and more considerably in level 2 and 3. The stresses were higher on the medial side in all cases. No remarkable difference was found in the patterns between the 4 stems.
  
  
  CONCLUSIONS
  The contour design of femoral stem has minor effect on initial periprosthetic von Mises stress distribution.
authors.affiliation: Department of Orthopaedic Surgery, the 6th Shanghai People's Hospital, Shanghai Jiaotong University school of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Kong-Zu
authors.initials: KZ
authors.lastname: Hu
authors.forename: Xian-Long
authors.initials: XL
authors.lastname: Zhang
authors.forename: Cheng-Tao
authors.initials: CT
authors.lastname: Wang
authors.forename: Wen-Ting
authors.initials: WT
authors.lastname: Ji
mesh_terms: D020342:Finite Element Analysis; D006622:Hip Prosthesis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008124:Locomotion / Q000502:physiology; D011474:Prosthesis Design; D013314:Stress, Mechanical