title: A new approach to prevent contralateral hip fracture: Evaluation of the effectiveness of a fracture preventing implant.
abstract: BACKGROUND
  Among the millions of people suffering from a hip fracture each year, 20% may sustain a contralateral hip fracture within 5 years with an associated mortality risk increase reaching 64% in the 5 following years. In this context, we performed a biomechanical study to assess the performance of a hip fracture preventing implant.
  
  
  METHODS
  The implant consists of two interlocking peek rods unified with surgical cement. Numerical and biomechanical tests were performed to simulate single stance load or lateral fall. Seven pairs of femurs were selected from elderly subjects suffering from osteoporosis or osteopenia, and tested ex-vivo after implantation of the device on one side.
  
  
  RESULTS
  The best position for the implant was identified by numerical simulations. The loadings until failure showed that the insertion of the implant increased significantly (P<0.05) both fracture load (+18%) and energy to fracture (+32%) of the implanted femurs in comparison with the intraindividual controls. The instrumented femur resisted the implementation of the non-instrumented femur fracture load for 30 cycles and kept its performance at the end of the cyclic loading.
  
  
  CONCLUSIONS
  Implantation of the fracture preventing device improved both fracture load and energy to fracture when compared with intraindividual controls. This is consistent with previous biomechanical side-impact testing on pairs of femur using the same methodology. Implant insertion seems to be relevant to support multiple falls and thus, to prevent a second hip fracture in elderly patients.
authors.affiliation: Hôpitaux Iris Sud, Department of Orthopedic and Trauma Surgery, Brussels, Belgium.
authors.forename: Marek
authors.initials: M
authors.lastname: Szpalski
authors.affiliation: Edith Cavell Clinic, Orthopedic Department, Brussels, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Gunzburg
authors.affiliation: Salem Spital, Orthopedic Department, Bern, Switzerland.
authors.forename: Max
authors.initials: M
authors.lastname: Aebi
authors.affiliation: Hyprevention, Clinical Research, Pessac, France.
authors.forename: Charlène
authors.initials: C
authors.lastname: Delimoge
authors.affiliation: SpineServ GmbH & Co. KG, Ulm, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Graf
authors.affiliation: Institute of Biomechanics, Trauma Center Murnau, Murnau, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Eberle
authors.affiliation: Hyprevention, Clinical Research, Pessac, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Vienney
mesh_terms: D000058:Accidental Falls; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000627:therapeutic use; D002102:Cadaver; D005260:Female; D005265:Femoral Neck Fractures / Q000503:physiopathology / Q000517:prevention & control* / Q000601:surgery; D005272:Femur Neck / Q000502:physiology / Q000601:surgery*; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000150:complications; D019736:Prostheses and Implants; D013314:Stress, Mechanical
chemical_list: D001843:Bone Cements
keywords: Biomechanical; Fracture prevention; Hip fracture; Osteoporosis; Prophylactic; Proximal femur reinforcement