title: In vitro implant-bone interface pressure measurements for a cementless femoral implant. A preliminary study.
abstract: OBJECTIVE
  Implants endurance as well as a good clinical tolerance depends on the recovery of a physiological stress distribution within bone after implantation. The purpose of the present work was to develop an alternative technique using Force Sensing Resistors (FSR) to gather in vitro pressure values at the implant-bone interface for a cementless implant.
  
  
  METHODS
  Eight cementless femoral stems were instrumented with six calibrated FSR bonded on each facet and then implanted in eight cadaver femurs. Compression tests were performed until failure and FSR pressure values were recorded.
  
  
  RESULTS
  The average failure load was 4241 N. The maximum contact pressure measured with the FSR averaged 1.965 MPa.
  
  
  CONCLUSIONS
  FSR reached many of the requirements for an ideal implant-bone interfacial sensor. This experimentation provided in vitro quantitative data on contact pressure at the implant-bone interface, which could help understanding stress shielding phenomenon and developing relevant numerical model.
authors.affiliation: Pediatric Orthopedic Department, Grenoble University Hospital, Grenoble Alpes University, TIMC IMAG - SPM, BP 217, 38043 Grenoble Cedex 09, France. Electronic address: aurelien.courvoisier@gmail.com.
authors.forename: Aurélien
authors.initials: A
authors.lastname: Courvoisier
authors.affiliation: Institut de Biomécanique Humaine Georges Charpak, Arts et Métiers ParisTech, 151 Bvd de l'hôpital, 75013 Paris, France.
authors.forename: Valéry
authors.initials: V
authors.lastname: Barbour
authors.affiliation: Institut de Biomécanique Humaine Georges Charpak, Arts et Métiers ParisTech, 151 Bvd de l'hôpital, 75013 Paris, France.
authors.forename: Wafa
authors.initials: W
authors.lastname: Skalli
authors.affiliation: Laboratoire de Biomécanique et Mécanique des Chocs UMR_T 9406 (IFSTTAR-UCBL), 25 Avenue François Mitterrand, Cité des Mobilités, 69675 Bron, France.
authors.forename: David
authors.initials: D
authors.lastname: Mitton
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005269:Femur / Q000503:physiopathology / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008875:Middle Aged; D011474:Prosthesis Design; D013314:Stress, Mechanical; D016474:Weight-Bearing