title: Prophylactic augmentation of the proximal femur: an investigation of two techniques.
abstract: BACKGROUND
  Osteoporotic hip fractures are an increasing problem in an ageing population. They result in high morbidity, mortality and high socioeconomic costs. For patients with poor bone quality, prophylactic augmentation of the proximal femur might be an option for fracture prevention.
  
  
  METHODS
  In two groups of paired human femora the potential of limited polymethyl-methacrylate (PMMA) augmentation (11-15 ml) in a V-shape pattern and the insertion of a proximal femur nail antirotation (PFNA) blade were investigated. The testing was carried out pair wise simulating the single leg stand. The untreated femur in each pair served as control. An axial load was applied until failure. Load displacement parameters and temperature increase during the augmentation process were recorded.
  
  
  RESULTS
  In the PMMA group no significant difference was found between the augmented and non-augmented specimen concerning load to failure (p = 0.35) and energy to failure (p = 0.9). A median temperature increase of 9.5 °C was observed in the augmented specimen. A significant correlation was found between the amount of applied PMMA and the temperature increase (Cor. Coef. = 0.82, p = 0.042). In the PFNA group, a significant decrease of load to failure and a non-significant decrease of energy to failure were observed (p = 0.037 and p = 0.075).
  
  
  CONCLUSIONS
  Limited V-shaped PMMA augmentation and PFNA blade insertion did not show any improvement in failure load or energy to failure. Volumes of up to 15 ml PMMA did not cause a critical surface temperature increase.
authors.affiliation: Department of Trauma Surgery, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria. christoph.raas@uki.at.
authors.forename: Christoph
authors.initials: C
authors.lastname: Raas
authors.affiliation: AO Research Institute Davos, Clavadelerstr. 8, 7270, Davos Platz, Switzerland. Ladina.fliri@aofoundation.org.
authors.forename: Ladina
authors.initials: L
authors.lastname: Hofmann-Fliri
authors.affiliation: Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Müllerstraße 59, 6020, Innsbruck, Austria. Romed.Hoermann@i-med.ac.at.
authors.forename: Romed
authors.initials: R
authors.lastname: Hörmann
authors.affiliation: Department of Trauma Surgery, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria. werner.schmoelz@uki.at.
authors.forename: Werner
authors.initials: W
authors.lastname: Schmoelz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000627:therapeutic use*; D015519:Bone Density; D001858:Bone Nails; D002102:Cadaver; D005260:Female; D005265:Femoral Neck Fractures / Q000601:surgery*; D005272:Femur Neck / Q000601:surgery*; D006620:Hip Fractures / Q000601:surgery; D006801:Humans; D008297:Male; D008953:Models, Anatomic; D058866:Osteoporotic Fractures / Q000601:surgery*; D019904:Polymethyl Methacrylate / Q000627:therapeutic use*
chemical_list: D001843:Bone Cements; D019904:Polymethyl Methacrylate
keywords: Cement augmentation; Hip Fracture; Osteoporosis; Single leg stand