title: Experimental and computational studies on the femoral fracture risk for advanced core decompression.
abstract: BACKGROUND
  Two questions are often addressed by orthopedists relating to core decompression procedure: 1) Is the core decompression procedure associated with a considerable lack of structural support of the bone? and 2) Is there an optimal region for the surgical entrance point for which the fracture risk would be lowest? As bioresorbable bone substitutes become more and more common and core decompression has been described in combination with them, the current study takes this into account.
  
  
  METHODS
  Finite element model of a femur treated by core decompression with bone substitute was simulated and analyzed. In-vitro compression testing of femora was used to confirm finite element results.
  
  
  RESULTS
  The results showed that for core decompression with standard drilling in combination with artificial bone substitute refilling, daily activities (normal walking and walking downstairs) are not risky for femoral fracture. The femoral fracture risk increased successively when the entrance point is located further distal. The critical value of the deviation of the entrance point to a more distal part is about 20mm.
  
  
  CONCLUSIONS
  The study findings demonstrate that optimal entrance point should locate on the proximal subtrochanteric region in order to reduce the subtrochanteric fracture risk. Furthermore the consistent results of finite element and in-vitro testing imply that the simulations are sufficient.
authors.affiliation: Department of Orthopaedics, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany; Chair of Mechanics and Robotics, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany.
authors.forename: T N
authors.initials: TN
authors.lastname: Tran
authors.affiliation: Department of Orthopaedics, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Warwas
authors.affiliation: Department of Orthopaedics, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Haversath
authors.affiliation: Department of Orthopaedics, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Classen
authors.affiliation: Department of Anatomy, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany.
authors.forename: H P
authors.initials: HP
authors.lastname: Hohn
authors.affiliation: Department of Orthopaedics, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Jäger
authors.affiliation: Chair of Mechanics and Robotics, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Kowalczyk
authors.affiliation: Department of Orthopaedics, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany. Electronic address: stefan.landgraeber@uni-due.de.
authors.forename: S
authors.initials: S
authors.lastname: Landgraeber
mesh_terms: D001696:Biomechanical Phenomena; D018786:Bone Substitutes / Q000627:therapeutic use; D002102:Cadaver; D003198:Computer Simulation; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D005264:Femoral Fractures / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control*; D005269:Femur / Q000601:surgery; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D008954:Models, Biological; D010020:Osteonecrosis / Q000150:complications* / Q000503:physiopathology / Q000601:surgery*; D013314:Stress, Mechanical; D013718:Tensile Strength; D016138:Walking / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology
chemical_list: D018786:Bone Substitutes
keywords: Compression testing; Core decompression; Femoral fracture risk; Femoral head necrosis; Finite element simulation; Surgical entrance point